As the local "weird possum girl", they are very intelligent! They shouldn't be!
See, opossum have smooth brains. This isn't normally linked to a high intelligence. Yet, they can remember if a food is toxic for up to two weeks after ingesting it, can learn and remember how to operate different sliding locks, and can solve simple puzzles with the right motivation(food)!
They can also form bonds, remembering people they like and dislike. Which is kinda funny to think about, because their babies spend a period of time riding around on moms back before they're big enough to waddle off on their own. If one falls off, she may very well trundle off, leaving the little one behind, who may hitch a ride on a totally different jill that happens to walk by.