How do you get her out of your house?

“One of my wife’s close friends recently went through a nasty breakup with her boyfriend, so she offered to let her stay in our spare bedroom. It’s been 4 months and she’s still feeling down from her breakup and she hasn’t made any progress on finding her own place.
It’s been exhausting having her around and I want her to leave. My wife doesn’t want to kick her out. What should we do?”