"We love all of them and spent a lot of time making sure we take care of them. I am on maternity leave currently and my due date is in three months. I decided to foster a litter of puppies along with the mama after I saw she was scheduled to be euthanized."
OP and her husband are clearly charitable people with hearts of gold, and sometimes being charitable with a heart of gold makes one vulnerable to be taken advantage of. We'd say that is exactly what is happening here.