Is being 13 and 145 pounds normal

Are pounds different depending on which country you are in?

I don't know, are you 5'7" tall (Canadian feet & inches) or taller, or are you 5'2"?
Really, can't you tell if you are slim, or chubby, by looking in a mirror? Really? Want to borrow my glasses?

That depends on how tall she is.

Kinda disagree with the above comment, I know groups of friends with age differences. Also no one follows the rules on this site.

Anyway, your friend sounds above average weight but not obese. If her weight isn't causing any problems I think she's fine. But if she wants to lose weight, she should simply exercise and eat fruits and vegetables.

Wait I found a flaw here. You are on a site for 18 year old and you have a friend who is 13. What are you doing around a bunch of 13 year olds? Also females at age 11 the normal weight is 90pounds and the the height is 5 feet. For age 16 average height is 5,3 120 pounds. So I don't know if that works for you.

When I was 13, I was 5'5" and 140 pounds. Now I'm 15, almost 5'7" and 145 pounds. I consider myself in the middle.
Don't worry too much about height/weight. Muscle mass and build is also a factor.