Do you think it's too young to...?

My little sister has a boyfriend but she's only in 6th grade. My mom is kinda mad and not sure if she should have one. I think that my moms wrong because she's only in 6th grade. Let her experiment and try new things. It's not like there going to do anything bad there only in 6th grade. She has the right to like someone. Besides, my sister goes to church and is a Christan. She never does anything wrong and is a very nice girl. Gets god grades. What do you think? Is my mom right or me?