Can you get pregnant when you are a kid?
If you have reached puberty, you can get pregnant, regardless of your age.
Yes they can if they have started ovulating. Even if a girl hasn't got her period yet she could still be ovulating. That is what you do before the bleeding starts. There are kids that has become moms at 12. However, it is illegal to have sex under age 16 in most countries.
It depends on whether the kid is alive and suckling the doe and when she next comes on heat. She could become pregnant technically within 21 days but usually they do not as she is more interested in the kid than the buck and farmers do not want their does to get pregnant more than once a year as it puts a large nutritional strain on the doe.