The hips will get larger. Hips require about 4 months from pollination t6o maturity. Hips usually turn orange or red at maturity.

Thanks, however the question still remains.
Does hip size dictate fertilization or does just the fact they have hips mean they are pollinated?
Thanks

1) You can't tell if seeds in a rose hip are fertile until you plant them and they germinate. Many roses make seeds that don't germinate. Its a trial and error thing.

2) if a rose produces a hip after pollination, and that hip stays on the plant for more than 6 weeks, then chances are fertilization of the ovaries has occurred and seeds will be formed. In which case, see 1).

Thanks for that info