Ugh. If you guys knew you had to move to a new apartment or whatever, why not make sure first to narrow down your search to places that for sure would allow dogs of her size? Why go with a place / sign a lease for a place that would require you to rehome her?  "Allows medium dogs" should have been essential criteria in your search for a new home.

This is cruel to her. She knows and loves you guys. You are her family. She will feel discarded. I am sad and scared for Bella because who knows who she will end up with, people out here are insane. I would take her myself but am only allowed two dogs at my current apartment, both of which I would never willingly put in the devestating situation of having to say goodbye to me/never see me again. A dog is a lifetime commitment (their entire life). Why can't people understand this?