So I think that's close to 4 1/2 lbs?
The rule of thumb is to double their weight at 12 weeks, but nothing is exact.
Wrigley was 1.13lbs at 12 1/2 weeks and she's now 6lbs even. (she's almost 4yrs old.)
However she had a big growth spurt after she turned 1! She was actually under 4lbs before then!
Crosley (she's a Yorkie-Poo) was like 3 1/2 lbs when we adopted her from another family and she was a little over three months and she's 17-18lbs now full grown!