Hi K.,
I guess that you have the other side of the coin. I also have a 17 month old girl, but she has nearly no hair at all. My husband continually asks her when she is going to grow some--as if she 1. understands, 2. can control it. :-)
When my oldest was just over 2, she started needing barrettes. I used the hair clips--look kind of like triangles--but not the normal size ones; the mini ones. I just used 3 one on side of her part and one on the other. She occasionally pulled them out, but not often. Mostly in the car, so I stopped letting her have them in the car. I used these for over a year and a half.