It is not unusual for Basenjis to enjoy sleeping in. Pretty much all of the five I have owned have been like that! One question: do you feed her breakfast when she gets up? I find a meal is a good incentive for them. Usually my boy shows up shortly after I prepare his breakfast.
I am wondering about how your current problem began? Just out of the blue, or did something happen that upset her? In any event, it is important that she realize bed is an option, not a right, and that bad behaviour will not get her what she wants. I think I would start requiring some sort of "work" before she is allowed on the bed, and as Debra suggested, a key word that means "get off", and enforce it if she does not comply. Stay cheerful, but use the leash when you must to get compliance. Try to head off any aggression by distraction. "Oh, Macie, look at that!" and throw a toy or something. Let us know how you get on.