C.,
I agree with the other two posts. Another idea, in case you HATE the crying and are feeling guilty, which we liked better was that we put our baby down for the night - complete with nightlight and sound machine, then sat on the floor. My husband did the first few nights, and vice versa. Each night we DID NOT make eye contact, talk to or acknowledge the crying or any behavior, And each night we sat closer and closer to the door. After about a week or more of this, we had no fussing, no anxiety and were "reading" in the hallway.
It's not as quick and easy, as the "cry it out", however we also didn't feel "guilty".
Another approach is to acknowledge the child from the hallway and simply say, "Mommy is here. It's time for bed." INSTEAD of going in. That's all you say, then walk away. Do not go in. Do not pick her up. If this makes YOU feel better to "check" on her or reassure her, then it's an in-between of sitting in the room or going in every 20 mins. We have done this too in the years since
"sleep training" our kids as babies. It works after chaotic holidays or long evenings out when their sleep patters have been disrupted. I read in my bed, down the hall from their rooms and will simply call out, "I hear you. It's time for bed." Usually my kids now know, it's night-night and THAT'S IT.
Even now, once in awhile our kids will "check" to see if we are listening to them on the monitor. As long as they don't feel abandoned they go right to sleep.
BTW - about your question, I wouldn't "time it" when you go in, if you go that route. Either make it one check and THAT'S IT or don't go back in. I do think you are training her daughter that eventually you will "rescue" her if she fights long enough. Also, don't reward her with a bottle!!!! If you've already fed and changed her before bed, then she doesn't need it. You are teaching her that Mom + Bottle = soothing & sleep. Not the message I think you want her to get.