Is it normal for your friend's daughters to maintain a crush on you?

My friends daughter has had a crush on me for years. We always used to joke about how cute it was when she said she was going to marry me when she grew up. We all thought she would grow out of it but she never has. She's in her first year of community college now and still sits close to me, holds my hand and wants to sit on my lap and cuddle.

Not that she isn't an attractive young lady but I'm 30 years older than her. She's never kept a long term boyfriend and always came running to me, not her parents when they broke her heart. Don't these crushes usually burn themselves out when the kids start dating other kids their own age?