Does anyone know how or if I can age up sims in another town? I moved towns and my family is still in the other. I want to be able to have them come visit but there’s toddlers.

You're in a separate household, I guess? In that case, go visit them in their neighborhood and then use MasterController to Trigger Age Transition on those particular sims that are toddlers. I can't remember the exact steps to get to that one, though unfortunately.