Hi there and welcome to YT !
I need to tell you that i brought my Suzi home when she was going on 9 weeks old. I took her to the vet two days later, she was 3lbs too. She was tiny and so adorable, It did not dawn on me at all about her weight.
Suzi is 11 months old and she is a 7lber. no kidding. my point is that it is hard to tell what there weight will be full grown! Suzi is happy, healthy and full of energy. If she were even bigger I'd love her just as much! She is a great eater and into everything!