She wants to play while laying in bed next to me she does not have a desk or mousepad or mouse.
I have no idea if it'd work, but this sounds like a good reason to get a
gyromouse. I don't know if they'd be responsive enough, but if I had one I'd totally give it a try.
In all honesty, don't try a controller. I've played games with an optical mouse against my leg or a blanket while in bed and it works fine.