I agree with Calliesmom... Bella is definitely too young to be left unsupervised, so you are right to be watching her like a hawk when she's out of her crate.
We brought our dog, Lerwick, home at 8 weeks old. He was not as quick to housetrain as some of the other dogs on this forum. He got the basic concept very quickly... but it took quite some time for him to realize it wasn't really optional... that it was ONLY alright to potty outside, and that rule was the same no matter whose house he was in. We have always had him on a regular schedule, as far as feeding and potty trips go, so that wasn't the problem. It seems he's just stubborn.
Transitioning from the crate to the house was a very long process for us... and right about the time we'd made the transition completely, he regressed (which I understand is typical of yearling dogs), so we've taken a few steps back. Here's what we did... maybe it will be helpful for you.
What we did to help Lerwick transition was to gradually give him more and more territory to roam, by blocking off areas of the house with baby gates. We started out letting him have free range of the kitchen (accidents are easier to clean up off a linoleum floor), with very brief, supervised, visits to other rooms only after a successful potty trip outside. I don't work outside the home, so we moved my computer out into the living room so that I could monitor him during the day. At night, and any time we had to leave the house, he was crated.
I don't remember exactly how long we stayed at this point, but I would guess it was maybe a month. Then we allowed him to roam the living/dining room (open floor plan, so one big room) and the kitchen. We stayed at this point for some time, because it took him awhile to work out that he couldn't/shouldn't just pee wherever he wanted in the carpeted area (living/dining room). Whenever he had one of these accidents, we would put him back in the kitchen for several days, with only short supervised visits to the living/dining room. Then we'd try again with free access to the living/dining room. As I recall, he only had about 3 accidents in the living/dining room, so it isn't like we were constantly cleaning up accidents or anything.
Once Lerwick was reliable with housebreaking in the living/dining/kitchen area, we gradually started moving the baby gate further and further down the hallway. We could always tell if we tried to move it too far, too fast, because he'd pee in the new area (this happened twice... once it was seriously a matter of 6 inches of new territory, but it was too far, too fast). Again, we'd move the baby gates back to kitchen-only for a couple days, then gradually work our way back to where the baby gate was when the accident happened. Then we'd hang around there for several weeks until we felt it was safe to press on again.
By the time he was 9 months old, Lerwick had slowly gained access to the entire house (well, all of it we ever plan to let him access... the basement is Kitty Safe Haven, so he'll never be allowed in there). We were letting him roam free--without incident--at night while we slept, and when we went out during the day. But at about a year old, he decided that it was ok to poop on the landing by the front door. And, if you were home and caught him doing it, he'd then eat it as fast as possible to eliminate the evidence!
So, we went back to crating him when we leave the house during the day, and at night we either crate him (if we want to leave our door open), or we close him in the bedroom with us. We've also moved our computers back out into the living/dining room (I've set up shop using the TV as a giant monitor, and Mike has his PC set up on the dining room table), so that we can monitor the front entryway better, and catch Lerwick BEFORE he goes. It has been a couple months since the last accident, but I have the feeling we're not out of the woods yet, so to speak. The last two days we have left him to roam the house while we made short errands, and have not had any problems... but I'm not ready to make a habit of it quite yet!
Hopefully some of this is helpful to you. If not... I apologize for my long-winded reply!
