Angie, I am so sorry for all that you and the family are going through. I lost my beloved dog, my beautiful little Toby, to congestive heart failure three years ago, much too soon and before his time. It is very difficult to see them struggle during the inevitable decline and wanting to do all that you can to help them and to hold on to them.
I hope that the vets are able to make your darling girl as comfortable as possible and prolong her time with her loving "pack" for as long as her quality of life and heart permits. Hugs. Wishing all the best for her.