Ya, she is definitely going in the wrong direction. At 10, there is still a lot that you can do about it. Trouble is you have to figure out what is causing the problem.
It could be her "friends" are unduly influencing her.
It could be she has something like ADHD which will cause kids to do things without thinking about it, and then many times lie about it cause they really don't remember doing it or don't remember why they did it. And, of course, is she has ADHD - her friends could really influence her the wrong way.
Either way, I would talk to her school teacher. Ask her how she is doing in school. Does the teacher notice anything unusual? What does the teacher think of the people she hangs out with? Does the teacher notice any signs of ADHD.
And here is a link to ADHD that may prove helpful:
http://www.medhelp.org/medical-information/show/2157/Attention-deficit-hyperactivity-disorder-ADHD?page=1#sec_3761