Head lice

My daughter and I got lice from a friends daughter.. I treated myself and have gotten rid of it. But using the comb hasn't been enough to get rid of it in her hair. Anyway the lice shampoo i used says 2 years of age and older. My daughter is 14 months. I am curious if anyone has had to use the shampoo on a baby younger than 2.. Or of there is a natural remedy i can use.