Hi Gabriel,
there is alot to say here.
First, you are both young and you are both going to encounter many growing years and changes throughout your relationship.
Nothing stays exactly the same forever.
Try not to be jealous and try not to complain about her gf in any way.
One thing all men need to understand is that women need women.
That never changes.
It will be a stronger need at some times than others and even take a back seat at times, but the need never vanishes.
Remember, what YOU can offer her is something NO ONE else ever can, as her husband.
You 2 do become one but always allow for your own personal identities.
You HAVE to accept each other just as you both are now because the root of our personalities don't really ever change.
Give her your blessings over her friends and you will be her hero!
Bless you!