I am 29 yrs old and have a large pw birthmark on my right cheeck. I am 5'2 and weigh 55kgs. I am a lot shorter than both of my younger siblings. Although never the shortest in my class growing up I was always one of the smaller kids. Although I dont know for sure I would be suprised if your daughters birthmark had anything to do with her height. I think it's more likely genetics and environment.