Need opionion on helmet for Plagiophaly?

Ok so my daughter had Torticollis and we fixed that through 4 months of grueling therapy, now she is left only with Plagiophally, the flat spot on her head. I don't think it's that severe and I don't think she really needs a helmet, but my husband think she does. Our insurance comepletely covers the helmet so that's not an issue. The doctors told us it would be entirely cosmetic and everything physical is fixed. What is your opinion.