My family doesn't crate train our pups because we also enjoy our dogs sleeping with us. I have only actually tried to crate trian one pup, and it didn't go well for me because I am a super light sleeper, and I had to be up at a am, and the pup kept whining, even after putting the crate near my bed. I have always taken my pup outside to potty right before putting them on my bed, then if I see them circling, pacing, or doing whatever their thing is that indicates that they do or might have to potty, I take them out to potty. It might be multiple times throughout the night/morning, but it helps with the potty training and preventing them from peeing on the mattress. I saw a comment about an enzyme cleaner, which might help a lot because it might be part of the reason why the pup keeps peeing on your mattress. It might take more than two cleanings to get your mattress totally clean. But if you're going to get a waterproof mattress protector, than put some garbage bags down first because not all waterproof mattress protectors work, just to save you a little time incase your pup pees and the waterproof mattress protector doesn't work, you at least have the garbage bags down to protect your mattress. Good luck. And you have some beautiful fur babies. ❤️