Here are some of the rules the girls have to follow (sorry for shitty English):
Storm will always remove 2 types of symbols entirely, prioritizing the shit symbols, then the girls and last wilds. You had 3 types of symbols left and a wild, so she removed the shit one and the storm lady, leaving you with love.
Star will obviously give you 1 or 2 wilds, but if you have an empty column between symbols she will land a wild there.
Love transforms one type of symbol entirely to another symbol in the grid except wilds, prioritizing the shit ones. She cannot transform wilds, she would just look stupid when triggered with only wilds left :p
The four girls trinity has been explained, you get a three of a kind (same girl) plus four of a kind different girls.
Knowing these rules can make you foresee a bonus trigger early in the trinity.