If you're going with your girlfriend, think about her capabilities as well as yours.
Don't over do it.
Hiking measly 4k'rs might not sound like much compared to the 14k're out west
But, the Adk's are actually quite challenging.
There's lot of rocks, roots, and MUD.
It looks easy on a map but,take my word for it, it's a lot more difficult than it looks.
I prefer base-camping and doing day hikes from there. I could reccomend some spots to hike with a little more notice.
Although I like backpacking over summits, the water situation is just to un-reliable, unless I knew otherwise.
All I can say is ,keep the girlfriend happy, if she's having a bad time you will too.
Good Luck, Be Safe, and have good judement.
Most of all, have fun!
Steve