My friend thinks shes fat.....?!?

My friend is 14, 5"4, and weighs 105 lb. She is very skinny. She thinks she is fat, and it gets me very nervous. She isnt doing annything about it, so i dont know why i am so scared. She costantly is crying to me about her wiehgt andi odnt know wat to do! the biggest problem is is that i cant say nehting rlly to her, b/c i also think i am fat (i am 5"0, 97 lb. ) and i alwasys cry to her... it oges both ways. I am scared for her, and i know she is scard abut me.. HELP!