Here is a couple of Ideas.
1. How about introducing a fruit or consumable item that swaps the gender of the spirits.
2. An option to make a better home then relying on the tent. Maybe even acquire items that can attract certain individuals when placed in or around the home.
3. Maybe generic sprites for the young spirits that haven't developed enough to tell what gender they are. Doing so when the player goes to the lake or something the player can sometimes spot them playing from the distance or sleeping.