pink slime half is better half of suggestion. lost girl is the weaker bit
pink slime gun would work better as just a pink slime debuff not blue slime+love(if anything then maybe debuff with an extreme sensitivity to knockback, but pure cosmetic would be my preference), but want all of the pink items (especially bouncy blocks)
also you should make the pink slime a stronger flamethrower ammo too
I want the moss seeds, liked the lost vanity/wig and nymph claw
probably not changelings(you'd have to do an extra nymph'd sprite and balance every new summon item(basically work of making two of them for every one), their effect seems meh anyway, i donno)),
some item to pacify nymph into a temporary merchant would be interesting (but not sure how well that'd work. does it announce her spawning? how does it know invalid housing(is it like where it says its missing only one thing? because that would probably stick her in a tree or random underground cabin, does she despawn(explodes like santa) when you remove the item? ect. just as easy to roll moss into dryad and stick the gem gun into a drop table somewhere with the claws as nymph's drop).
should make little sis staff male : p skincolor doesn't determine gender