Goodmorning.............I am feeling your pain.........I went through the same thing about 4 months ago. I am no expert, but I think you need to control her area for awhile. First of all so she does not poo & pee on your carpets, I would only let her in the kitchen. She has never poo/peed on my carpets. And when she went pee in the kitchen I was upset, but it is easier to clean up. Either have her in the crate or in the kitchen w/ a gate. We use to sit out in the kitchen w/ her on the floor. It is very time consuming and that is why I was probably at my wits end. I was ready to sell her, but I am sooooo glad I did not. We took her outside every 1/2 hour and praised her constantly.
You will succeed w/ confining her, if you have something to do put her in her crate. If she cries toughen up and let her cry. Never take her out or she will know that is the way to geet out.You have to watch her every minute. At the end it will all be good. Cuddles has not had an accident since she was 5 months old. And you cannot say weight has anything to do w/ it cause she is only 3.5 pounds. They need to be trained and know who is the alpha.
I hope you try it cause it worked for us.
God Bless You