Dog Bad Habits-need advice and home placement

Question:
 I adopted a mixed breed female lab 5 months ago as a companion for my border collie/lab male. The female is 2 1/2 years old and seemed like a good candidate for adoption-her family was to relocate outside the US due to a job change and couldnt take their doggy with them. Long story short, I have come to find out that this family is not leaving anytime soon and the dog has many, many bad habits that I am trying to fix. When she first came to the house, she was friendly until her owner left. Then she cowered and hid in her crate. She growled and rushed at anyone coming into the house, and bit me the second day of her stay. It didnt look good, however, we found she was extremely afraid and gained her confidence. She has not bitten anyone since and is comfortable with our family. We have had a couple of close calls with snapping at guests to the home-mostly children. But no problems with her attempting anything with my 9 year old. We thought she was doing well with our male dog-she was starting to learn how to play nice and would give chase and wrestle with him. However, the other day she viciously attacked him with full teeth and snarling. Something I had never seen her do before. My male was not hurt, but he shrieked in fear and exited the area. Now he is wary of her and tries to avoid. That troubled me because he was the reason why I got her in the first place. Both dogs are fixed, by the way. In addition to this, her potty habits have been on again, off again. Even though I take them out several times a day for play (the border mix needs frisbee play several times a day, and she chases him for fun) and walk them once a day. Took her to the vet-nothing wrong. There was no rhyme or reason to the accidents. She would be fine for a month, then several accidents in a week, etc. This week it was full bladder of urine that has discolored my hardwood floor. Then she occasionally will chew up fabric items (like my comforter, or her dog bed) and I cannot seem to get her to stop getting in my face or pushing my male out of the way when I try to just pet him. She is very insecure and acts like she needs all of the attention. When I try to correct this behavior by saying her name and asking her to lay down or leave the room, she paces the floor with her head down, cowering and shaking her rear end. I dont even need to raise my voice for her to react this way. In her defense, she is an extremely loving dog. When we gained her confidence, you couldnt get a more kissy, cuddly dog. Since she has been here, she has learned to play, explore her surroundings, found her puppy leg, smile that silly doggy grin happy dogs get , not submissively pee anymore and now will voluntarily get into and ride in my truck. She also listens wonderfully to our commands in our wooded, unfenced backyard. Its been alot of work and she has come a long way, but I am tired. The reoccurring accidents and her occasional aggressive streak has worn me down. My husband has been patient and hasnt said much, but I know he is done, too. Humane League of PA will not adopt her out due to the snapping situation and housetraining issue-they offered euthanasia. I dont want to go that route considering she has made improvement in the past several months. But placement will have to be a special situation. And I dont know if It is a liability for me if she bites the next person who adopts her? I sent an email to her old family, to give them the option of taking her back (her owner has asked for email updates and photos of the dog to see how she is doing). Does anyone have any suggestions on what I should do. As you can tell, I am feeling extremely guilty that this didnt work out. Help!
Answer:
 She came so far in the last 5 months, give her a few more months and she may be perfect! There's always the fact when you adopt an older dog their habbits and personalities are already formed. I understand your feeling guilty about wanting to get rid of her. We had bought a couple female baby rabbits 2 easters ago for the kids. It turned out to be a nightmare. One was a male so we ended up with a litter of babies to raise, before we could get rid of them she was pregnant again. (They can get pregnant the day they deliver, that's how the second litter came about.) The mom died from the stress and we had 12 babies to hand feed and find homes. We kept the dad and two babies, but they bite and are mean, but we feel guilty about giving them to the humane society because they would just kill them. So we're stuck with rabbits to feed that are not really good pets.
Answer:
 i agree with suer, give her more time and consistancy like you have been youve brought her through alot. the dogs are establishing hierarchy,thats totally normal. usually they dont hurt one another badly unless the size difference is extreme it should be alright. still correct them but dont stress. get some bitter apple to spray one things she chews on and use a crate until she gets back on track for potty training. dogs are den animals in the wild and a crate can be a place of comfort and quiet. take her out and stay with her until she potties and praise praise praise. youre doing great.