I went through this with a tenant just over a year ago (Madison County, IL). In IL landlords can enter the property with 24 hours notice (I think this is common). Give her the notice then go over to check the place out.
Also I found my county courthouse to be very helpful in walking me through the eviction process. The process isn't always landlord-friendly (especially in Illinois) but with proper guidance it's navigable.
My story: The tenant was avoiding me because the 5-Day notice to vacate must be served in person. So I told her I was entering the property "24 hours from now" every day for about five days. After that she had no idea when or whether I was showing up, even though I had checked the box for 24 hours notice.
Finally I did show up. I requested law enforcement to join me mainly so there'd be a witness to any bad behavior and to protect me from any accusations. It was hilarious to see her come out of her bedroom in lingerie to "negotiate" with me, only to be startled by the presence of the police officer. She grabbed a robe. Short story: I served the notice and she's gone.
Good luck! I've never done cash for keys but that's probably better and quicker. Just don't pay in advance!!! And if you decide to evict you can do that successfully. Just rely on the advice of the experts in your county courthouse.