Help Save Dixie

This is sweet, 9-week old Dixie. She is a Miniature Pinscher/Rat Terrier mix. My sister and her fiance got this puppy a couple of days ago as an early Christmas surprise for their two children. When they first got her, she seemed very sleepy, as some puppies can be. Within a day, she became severely ill, lethargic and wouldn't eat or drink. My sister brought her to the emergency vet and they diagnosed her with Parovirus, which will cost between $3,000-$5,000 to treat for her to survive. The vet said that the breeder may have had unvaccinated dogs that exposed her to the virus. The woman they paid $500 to for the puppy has not returned their calls. They had responded to her Uncle Henry's ad and she never gave her full name. She met them at a rest stop to drop off the puppy because she was "heading their way." They have a feeling she knew that the puppy was sick, but sold her for $500 anyway. My sister is a huge dog lover and my niece has already fallen in love with Dixie, so she couldn't just have her put down. I know it's the holidays, but my sister and her family would be so grateful for any help they can get. They would love to get their puppy healthy so that she can have a happy life with them. They will definitely pay it forward in the future. Thank you!