Next time she wants to come over I would say "No, I don't want you around my "stupid" dogs". Sounds like my aunt. She kept comparing her daughter's dog to Sassy saying how she was well-behaved and she never peed on the floor. My mom just about blew her stack and actually got pretty nasty with her.

I'm sorry your aunt said that to your brother, who cares? Her life is not enriched with the love of a dog, you should pity her.