Originally Posted by ZOLANTON

??? I don't think that's true, when my girls were level 40, I could use the help of people whose girls were at level 50. I don't know if it's capped at a certain point but it surely doesn't apply in evolutions.

It's capped at the highest level girl you have in your team. Basically any friend helper that is higher than your girls gets nerfed down to your level. Note that it only goes by level, not evolution level. So a level 50 evolved character won't be nerfed unless you have no level 50 non-evolved or evolved in your team.