She does not understand why I bring work into the house, and says that it detracts from me enjoying quality time with her.
It can't detract from you enjoying it, but maybe from her enjoying it.
If she means that it detracts from her experience of spending time with you, then she absolutely in the right to express that and that makes total sense to me. Doing stuff with the other person is completely different from doing separate stuff in the presence of them.
But, for me, us doing our hobbies side-by-side like this is pure heaven.
That also makes total sense: as long as you're each doing separate stuff, it's cozy to do it in the same room, together. But that doesn't mean that she's wrong in wanting to do stuff that's actually doing stuff with you. A conversation, a game, or some other activities.
I would feel the exact same way as she feels here. I think what she is saying is 100% legit.
Please understand the difference between doing stuff together in the way she means it vs doing things together in the way you mean it.
Now, what to do about it?
First of all, she is 100% allowed to bring this up, express her desire for wanting to do stuff with you. And you are allowed to say that you don't wanna, that you'd rather spend your time on your computer (with her beside you, doing her thing). You are both 100% allowed to feel the things you're feeling here and there's no need to fight about that.
Now, then the next step is: what happens if either person insists on changing this situation? What if either of you says "It's my way or the highway?" That can happen and then the other person would need to make a very stark and difficult and heartbreaking choice.
It doesn't have to be super binary, it can be "one night a week, let's do it my way and the other four, your way".
A mutual hobby can be so awesome. It doesn't have to be a new thing; the two of you can work on her sketches or on your [what is it... programming?] together. Or it can be a new thing.
My number one issue with the guy I'm seeing right now is that I wish we could just see each other more often. And by that I mean actually interact.
What you mean by quality time (doing separate stuff in the same room) can be so valuable and relaxing and precious, and I get why you need it and want it and want to continue it. But, she can't enjoy it fully since she's so starved for interaction with you, longing for you, to talk to you and/or touch you and/or work on stuff with you like a boardgame or hobby project. As an analogy, I can't enjoy sleep if I'm hungry for actual food. She is starving for your attention, not just your presence. Being "just" in the presence of each other can be so great but not if you've got a hunger that has not been met.
Now, as I mentioned on fedi the other day, I like to solve all relationship advice by listening to Alanis' "You Owe Me Nothing in Return" a couple of thousand times on my own until I think I get it. What that means in this context is that neither of you is obligated to acquiesce to the other's wishes here. People are themselves, belong to themselves, do what they want to do, and when and if those things match up with the other person, that's great.
But whatever you decide to do, do so with awareness. Know how she is suffering and starving in this status quo. Then when you have that full awareness of the situation, when you know it's not just "why can't she just enjoy this as it is", when you know that she wants something else and why she wants something else, then you can listen to your own heart and make your own choice about how to resolve this.