>>44941089She as making her way away from Lumiose City, but got captured by a poacher, probably for her horn or as a slave. Professor and Elaine thought Astrid was mad at them, so they gave her some space, but after a few weeks went by without any messages they went to go look for her. Elaine's new heightened psychic abilities made it easier to track her, when they found her Professor disguised himself to get the drop on them and teleport away while the poacher was incapacitated by Garchomp's hyper beam.
Professor also might have adopted a Lopunny, but you should probably ask her about that. 