The tiny pup was adopted this past Thursday by Brent Stache and Jenny Stache of Oak Creek, Wisconsin.
Though Thumbelina may be small, she has a big personality, Brent Stache told ABC News today.
"She's very needy as far as attention and always wants to be petted and loved," he said. "She gets excited meeting people and is always asking to be picked up and played with."
The little Chihuahua first came to the Wisconsin Humane Society's campus in the city of Racine right before Thanksgiving, according to Angela Speed, the humane society's vice president of communications.
Thumbelina had been surrendered by a family who could not take care of her due to financial reasons, Speed told ABC News.
At the time of her surrender, Thumbelina was 7 weeks old and weighed just 0.64 pounds, Speed said, noting that "Thumbelina was about half the size of a normal Chihuahua at that age."
Now, Thumbelina is 3 months old and about 1.54 pounds, according to Speed.
Based on the pup's growth rate, she's not expected to get any bigger than 2 pounds, Speed said.