How to Handle Child's Moodiness?

I think you need to cut her, and yourself, a break.
Stop trying to "keep her happy" all the time. That's so unrealistic, as you know. You are mother and daughter, REAL people, not an ad in a magazine, it's natural and expected for BOTH of you to be cranky from time to time, even daily believe it or not.
You keep doing what you are doing, which is the best you can, I am sure.
Make sure you are also taking care of yourself (diet, exercise, friends, social life) because if you don't that will only make you a more miserable and less patient mother.
Your daughter may be your top priority but that doesn't mean that she should be your ONLY priority.
Truly spoiled and obnoxious children are created by parents who raise them believing nothing else is as important as they are. But of course that's not true, we are ALL important, including YOU!

That's tough- I feel that way sometimes too. I think the responders below me have good points.
I realized something about my family recently that applies. My husband has been under tons of stress and is at work most of the time. When he's gone things with the kids are great. When he's home my 5 year old is a wreck- whiney, rude, etc. I finally realized two things- first, it's because of the stress. They don't understand that it's not related to them or know what it is, they just feel it and react in crazy, five year old ways. Secondly, even though I swear he's super compassionate for his age, he is just 5 and 5 year olds are naturally self-centered. They don't really get the whole 'I'm stressed and busy can't you just play nicely for a minute' thing. So as frustrating as it is you have to let it go as normal. I think cuddling, being positive and reassuring has helped.
Also, at times I've told my 5 yo "I don't like the way you're talking to me, please go in your room until you're ready to be nice." Usually this is followed by him crying, but I try to ignore it because you're right- we shouldn't cater to them all the time- and eventually he returns a little nicer.

I think this is an age-old question - how do we not take our kids' stuff personally? How do we let it roll off of us? Frankly, if you find the answer, you will be a multibillionaire when you sell it. :)

More seriously, it's important to remind yourself that it's not about you; it's about her. When she tries to get a rise out of you, ignore her; if there's no reward in it for her, she'll stop eventually (but it will get worse before it gets better). When she's grumpy, empathize with her disappointments, anger, etc. but don't engage. Have a boundary between her grumpiness and you. When she is pleasant to be with, praise her tremendously; kids respond well to hearing positive things. And I hear that you're a stressed out, busy single mom, so it's hard to find time for yourself, but I wonder if just 5-10 minutes a day, maybe before waking her up, you could meditate. It will center you and help you to stay calm.

Of course, all this is easier said than done. That's where the secret to becoming a billionaire comes in!

Also, I disagree with the person who says that she is emulating you. First, as a parent, you have to be firm with her at times, and she is not your parent so she needs to learn that she can't correct you. Second, kids get grumpy, mean, etc. Maybe they learn it at school. Maybe they learn it at day care. Maybe they just innately have mood problems. Whatever the case, a poorly behaved kid does not always mean that the parent is at fault. I wish more people understood that.

Good luck!

I had someone tell me once that kids are like mirrors. They don't know how to deal with the world around them, so they look to us, their parents, to find out how to act/react. If you're grumpy and stressed out all the time, and she's giving you trouble because she's grumpy...well, why do you think she's grumpy?

You wake her up in the morning and everything is great. But then you realize you're running late for work...so you snap at her to hurry up and do this, do that. You don't think that's going to make her grumpy? I know it's hard, but don't let her see you getting stressed out. Keep a smile on your face. When you put her to bed at night, go take a hot shower, or soak in the tub. Spend some time alone with you to unwind, and destress. This will help you, and in return help your daughter.

*hugs*

One of the many secrets to a happy life is to fake it till you make it.

If you want to be one of those people who make their own fun and it lifts your mood, then do what they do till you have one of those families that make their own fun. It's hard work to pull yourself out of a rut but if you keep doing the things you are doing it won't change this dynamic.

Your daughter won't be happy all the time, period, but you can try a few things like music. Yesterday's question on how to get yourself out of being irritable involved a lot of happy music. Turn the music on and dance like crazy for 10 mins when you feel the mood go south, Random Dancing moment! Keep a puzzle going at all times and take 10 mins between jobs to grab success. Chop extra vegetables on a day together. Do a 10 min cleaning burst. Make your alarm on your phone go off at random times in the evening to do short bursts of activity. Break the chain of irritation and build a bridge to get over it!
Some of us are more sensitive to the moods of our children than we ought to be. That's not easy to change so start try to change it now!

You said it yourself - "I am always stressed; It seems like she is emulating me; balancing my own misery and stresses in life". She is reflecting YOU back at you. Her negative and mean is reflecting from your negative. When you do something special, you probably put the stress aside, and you are BOTH able to relax and enjoy each other. Real life - your stress is back and back things go to the tension.

Kids are radar dishes for the adults in their lives. If I am in a bad mood or having a hard time, my son will pick it up and reflect it back, and since my patience is thin it makes it even harder to feel better. Your child is picking up your misery and reflecting it back at you, and you can't cope. It sucks, I know. Somehow you have to get some down time, or some therapy, or do yoga together, or something so YOU can de-stress. That's the key to this.

My hubby is working out of town for long stretches, so it's just me. I don't really have a sitter, and I'm not super social, but I do need down time. Two things I do: 1) eat lunch, then go to a McDonalds or something with a play area - bring a book, ipad, whatever, and relax and do something you like while your kid plays. 2) join the YMCA if you can - their family rates are ridiculously cheap for the bargain you get - classes and childcare are INCLUDED in the membership. I take Zumba 2x/week so if I had to pay for classes and childcare, that would be $80 for childcare, plus another $80 for the classes if I didn't belong to the Y - monthly dues is $60 for the family. They are open till 8pm, and are also open on the weekends (but only Saturday am childcare).

I have been living with grumps lately too. It's so hard when we get so little time together and then it is spent in sour moods. So what I do to get myself out of thinking that way is to remind myself how valuable the time is that I am teaching my kids to behave better and that it takes a lot of practice. My mom was single when I was 12-14 and she annoyed me so much. I couldn't stand the way she talked anymore, her gestures, the way she put on her best front in public. I eventually got over myself. So I try to remember that my kids being unhappy with our crazy, messy, needs halfway met lifestyle is normal and I can help them to work their way through this.

I am also a single mother trying to make ends meet pay the mortgage and other bills and get by. I hear you. Not only the financial but the stress of a bad relationship and other stresses of life.
I wish I had some advice. My daughter complains that her friends get to do this or that and here I am trying to juggle Christmas presents new winter gear (Jacket, snowpants, boots) AND a $200 ski pass to the local mountain since she is going to be on the ski team. Which to some better off families may not be a big deal but when I have $250 in my bank account, that's a little scary.
So, wish I had something to tell you. I think some of the other people may be right, what you show your daughter she reflects. However I hope that you understand you are completely normal for having the feelings you do and I wish you the best of luck!!!!!!!!!!