I'm 13 and I don't have any money for a computer?

Hard time's being young my friend… Minecraft is all fun and games, but sometimes there's more important things in life such as food, clothing, water… Wait and save up even if it's penny at a time. Invest the money you save up on a way you can make even more money faster such as a lawn mower. It could take a while but it'll feel better mate. Your mom might sound mean not giving you the money but she might be having money problems at the moment. Good things come to those who wait.

A thirteen year old does not need a computer. Your mother is clever not to supply you with one.
Peace.

Btw. Neighbours, family and friends do pay for chores.

You haven't asked a question. Are you trying to ask us for money?