C.T.
She's growing up maybe she wants to be treated more grown up Maybe start talking to her like an adult...have "adult" conversations that she can listen to and take part in. Take her out for a mom/daughter "date" and do grown up things. (This is also a good age for dad to take her out on a date to show her how she should be treated when a boy takes her out, ie-coming to the door, meeting the parents etc...but that's a completely different issue.)
My nephew is this age and he tries to get in on adult conversations as well, it drives his mom crazy and she tells him, "you don't need to know everything that we are talking about" of course it doesn't really do much good. I think it's part of becoming a teenager-which btw I don't look forward to. My dd is 4 and she tries to tell me what to do! She just needs to know that is completely unacceptable, you are the mom and she is the kid and it is not her job to tell you what to do. The smart mouth thing might need a little sassy spray, equal parts vinegar and water in a spray bottle, my daughter runs from it. (also excellent as a natural disinfectant..lol) God bless, say lots of prayers, you've got a few years to go!