How to get my mom to not feel sad about me going into the army reserve?

I know i can't changer her mind now cause i am 17 but i turn 18 in august and i am going in. What would be the easiest way to tell her that i am going in without all the tears and everything. She is just worried that i am going to go to the middle east and die. That is the only reason why she won't let me go in now. Also, now with the army reserve do i go to basic for 10 weeks and all that or do i just go for 2 weeks a year and one weekend a month for training? Also