My daughter is 15 years and 5'4. she's very insecure about her height. i'm 5'5 , her dad is 6'1 and her sister is 5'6. can she grow taller and how?

Possibly: If an estimate is done with parental height, her expected final height would be about 5'6.5". A simple x-ray of the left hand & wrist can be assessed for bone maturity. If the maturity is close to 13 she is likely to grow taller; if closer to 15 his further growth is limited & she may 5'5" .Proper diet & rest provide the best support for normal growth.

Maybe, see below: Taking mother and father's height and calculating a mid parental height prediction, it is likely she could be up to 5"6". However, we would need to know what stage of puberty she is in, have her growth plates closed, has she been on medications that may slow her growth. The best would be to ask her pediatrician these questions. Remind her she is at 50% height for a woman, at 5'4", and not short.