I would take her to her pediatrician.
My dd11 has had "warts" on her legs for over a year. They spread slowly from a one or two here and there to all over her inner thighs. They looked horrible! Some got all red and swollen. On adults they go to the genital region - OUCH! Her ped. told us several months ago that it is moluscum contagiosum, and is very common in kids on the legs.
It's very contagious, but my dd is not self-conscious about it. This summer they appear to finally be drying up. I read on medical sites that there is very little that a dr. can do for them. They go away on their own w/in 12-18 mos., which is how long it's taken for my daughter. You can poke them with a sterilized needle - for my dd that was NOT an option! There are products available on the web that claim to work, but when you research them, they work for some people, not for others. I chose to just let them heal on their own, and it's apparently working.
Again, only your daughters dr. can make the diagnosis, but if that's what she has, I can only tell you I've been there!