Welcome to YT..Here is a growth chart..is will give you an ideal of what she may weigh at different times ...right now looks like she should be about 4lbs.when grown. What size are the parent? Did you see the parent?
http://home.comcast.net/~kkingpdx/puppygrowthchart.html
My pup is about 18 weeks and she is about 47 ozs. It show mine should be about 4.5 lbs. Her parents are 4.5 lbs and 3 1/2 lbs.
Good Luck to you and your new little furbaby