Tammy I so sorry for all you've have gone through. Livi and her puppies are very lucky to have such a devoted family caring for them.
I had to feed Harmony's small girl for over a week. The bottle didn't work for us so I used a tiny syringe. I would give her some nutridrops right before feeding her and it seemed to really help. It worked out great because I could control the flow and amount so much easier. Harmony didn't have much milk either when her pups were born. It took over a week for it to come in strong but the whelping pudding and letting the pups try to nurse helped bring it in. Just make sure Livi is getting some calcium and being stimulated. There is a supplement called Happy Jack Milkaid that is suppose to bring in the milk and is said to be successful even when previous litters there was none. Maybe you can have it rushed to you right away?
Milkade
They didn't double their weight their first week either. Angel really worried me because for a few days it didn't seem she was gaining any weight. But her tummy was full and she seemed content. She did start gaining afterwords just took some time. Just as long as they aren't losing they should be alright.
I wish you lived closer, Destiny wouldn't mind being a donor mommy and she has more milk right now than she knows what to do with.