Frankly I'd have a great deal more sympathy for your situation, had you not left the dogs outside to go ON VACATION. If you had to leave on a moment's notice to take care of some business, or family issues, or anything unexpected like that, I could understand. But you plan out a vacation, and therefore you must have planned out leaving your dogs with your mom who apparently doesn't like dogs enough to allow them in the house. What happened to your household because of your brother is unfortunate, may it be a lesson to you to take your dogs into further consideration when you plan a future vacation?
I understand that the unexpected happens, I am glad that things are okay. Boarding kennels are your friend, especially with a bite-risk dog. Find a kennel who is willing/able to deal with your kelpie, for the safety of your dog as well as the people who might come into contact with her.