Do you think she is too skinny??

C
I have a very happy 3 month old daughter, but people keep telling me she is too skinny and something must be wrong with her. She was born 20 inches long weighing 7.8 lbs. At her 2 month check she was 24 inches and 11.6oz and yesterday she turned 3 month and measured 25.5 in and 13 lbs. I know she is super long and definitely lean, but she seems totally fine to me, even though she's not one of those cute chubby babies. 
Btw, she drinks 24oz each day, basically since birth.
What do you think? Is this normal? Should I worry about her weight?