Lindsay Frost becomes one of Madison's friends in the series. Madison had known her since first grade, but never really knew her well. She was first featured in the 3rd book, Play It Again, as the girl who had an incredible voice, but was very shy. Her parents were going to be divorced, but it was never mentioned after the 20th book, All That Glitters. She was often bullied by Ivy and her drones due to her weight, and often thought she was fat. Madison, Fiona, and Aimee always intended to boost her confidence level.
Madison and Lindsay knew each other since first grade, but never very well. Madison knew her as the girlwho had an incredible voice, but was very shy. Lindsay always thought she was overweight, but Madison always tried to raise her confidence. Lindsay invited Madison to her party in New York City, where the two became closer. When Lindsay said her parents we're going to get divorced, Madison comforted her and it became something they had in common.
Lindsay and Fiona quickly became friends after Fiona moved to Far Hills from California. When Lindsay ever complained about how she or other kids thought she was fat, Fiona often came right out and disagreed with her. In the later books, the two kept in touch over bigfishbowl.com. Lindsay is BFFs with Mdison, Fiona, and Aimee.