I have read the Breaking Dawn, as well as the prior three, and I was wondering and I don't want to reread it to see if its in there. That while Renesmee was aging would she stop at some point? and also what that would mean for Jacob?

Nessie will reach physical maturity after about seven years, when her physical appearance will be around seventeen, and then stop aging.
Jacob is a shape-shifter and as long as he changes into he's lobo form regularly he won't be aging also so there's nothing to worry about.

yes, when she is about 7 to 10 yrs old she will stop aging and look like a 18 yr old girl and jacob doesnt age until he stops shape shifting sooooooo ya.

renesme will be fully grown in 15 years or something and jacob is fine with it

Well, we all know she is going to mature in 7 years and Jake can't age if he continues to phase. Let's not 4get that Nessie won't age again so...

Solution:

Jake should never ever stop phasing!