Well you're only talking about a few hours here - and perhaps there might be something she might like to do on her own in those few hours. It sounds like she's more than happy for you to go & enjoy yourself, and I think you should accept that in the spirit it's offered.
Sounds like a really good omen for a happy relationship if you don't feel the need to be joined at the hip.
Perhaps you could think of something really nice to do on Sunday to show your appreciation of what a great attitude she has.

Kris