Is it normal to be horny at the age of 12?

Plzzz do not laugh at me , its really embarrassing and im kinda getting these weird feelings i wanna have sex. soo i started to finger myself (ps im a girl).so i wanted to know if its healthy to do that. and is it a sin cuz my religion is christianty.and im terrified if its a sin. and plzz do not laugh. im kinda scared if what im doing is bad