Do you think my friend cuts herself? Help!?

One girl in my class has moved to another school and back to our school. She has dyed her hair black and has started wearing jackets everyday. She has told me she has cut herself before. But another thing is she is a liar. (Sometimes) But anyway today I was helping her with her homework and she STILL uses her fingers to count and I've been trying to help her not to and I told her to put her habds on the table so she wouldn't and then she was like I don't want you to see my wrists. And I was like why.. She was like can we just get back to my homework I don't wanna talk about it. Then I was like are you cutting yourself again? She said can we please get back to my homework... I sorta freaked out because I don't want her to die and I'm not sure if shes trying to look cool or what.. Then after that she said she only cuts her ankles. She kept saying lets get back to homework.. Do you think she is or what.. :/