So I was wondering how much HRT is going to affect me.
Will if have any effect if the females in my family have big breasts???

Sorry for the silly question! 

Probably a lot but it depends
And possibly but it depends

You're very young so you will have better results with everything. But some people just don't have estrogen receptors. My friends are blown away at my breasts after only being on E a little over 3 months but they still seem small and lame to me. I'm still just an A but they seem to be growing at a steady pace.

It will take several years for them to mature to their full size, so it's silly to be discouraged too early.

Yup!!!

Yer boobs will be so big you'll need a wheel barrow to carry them 

Just kdiding 

Everyone is different, but if your mom and sisters have big boobs, there's a good chance your in luck