size/weight

Question
I am considering an adoption of a Boxer puppy.  I have been looking for a small dog.  Currently we have a Boston Terrier and we are looking for a friend for her.  What! boxer - small you say.  I found a 6-8 week old Boxer puppy that is 1 pound 2 ounces.  I figure she is not a purebred Boxer, but is there a way to know about what her full size would be.  

Thanks for your time

Answer
If not purebred Boxer, I would not have any way of predicting her size not knowing the other breed mixed in.

Average adult female Boxers weight between 50-75 lbs. and average adult males Boxers weigh between 70-90 lb.s (if not more due to their family genetics).