This really sucks, I wish I could help you. I think it sucks that your mom can't keep them. But, if the tables were turned and she was getting rid of her dogs because they didn't like her cats, it would be just as upsetting to a lot of people in here. I don't know y'all's situation, but, I usually tend to give people the benefit of the doubt. I mean, you're obviously pet lovers or you wouldn't even be putting this effort into rehoming them. You would have just taken them straight to the pound or something. I mean, it's disappointing that the animals don't get along, and, as long as everything has been tried as far as teaching them to get along, then, this sounds like the last resort. But, if it's the difference between the cats living in a bedroom with dogs in the house that don't like them, and, finding them a home where they can roam around, undisturbed, then, I think you're doing the right thing. What kind of dogs are they, anyway?