Glad to hear you're enjoying the game!
Having a good environment and quality growing conditions are great for your mushroom, but it sounds like you might be giving your daughters too much. Your daughter needs more experiences to grow up into a healthy woman! Also - if you are running out of resources often, it may leave you with less time to raise her properly.
(More specifically: Little Brown Mushroom happens when your mushroom girl has particularly low stats... something Environment doesn't help with directly.)