Take her for a walk or run before you leave. Then give her a treat and go when she's resting. I wouldn't worry about the sleeping as long as she seems otherwise healthy. Beagles are pack dogs so if you get a friend for her she'll be very happy. If you can hunt her she'll love that. If you don't hunt, think about letting her go with some other beagles on a rabbit hunt. You'll be suprised how much it will help her calm down.