Advice

I need a little advice I have a 10 year old daughter and since she’s turned 10 (bday is Valentine’s Day) I’ve noticed she’s just been moody or extremely irritated almost all the time. She’s already started to develop her chest and she’s starting to grow hair I don’t know if it’s because she’s about to possibly start her menstrual cycle but I don’t know what to do. I try to stay calm with her but it doesn’t work and then I start getting frustrated because of her attitude and her mouth