is a 1 month old baby suppose 2 be 13 pounds

my little one was 20.5 lbs at 6 months old. when born he was 9.8 lbs. so yes they could be

It's a possibility. my daughter has gained a little over 3 lbs since birth and she is 8 weeks old.

8lb 15oz@anna.atterberry

depends on how much they weighed when born.