“Laser hair removal treatments under arms”

Seeking help:

My daughter took her first laser hair removal treatment on her underarms. She had pain for a couple of days and the discomfort that goes along with the treatment. With highly busy high school life, she wishes to take rest of her treatments during the winter and summer school breaks. I know the minimum recommended time period between two treatments but is there anything like maximum time period? Does one loose the effectiveness of the previous treatment if the second treatment is taken after 6 months?