i completely understand your frustration. who would want to come home to that?
I've read a couple of your other posts and i see that she is not a puppy but a few years old. I'm not sure which type of ex-pen you have but if its the standard wire one you can buy a top for it.
Midwest Exercise Pen Top - Kennels - Crates & Kennels - PetSmart you have to make the pen into a square and you can get a wire or mesh type top.
I have an ex-pen and a crate for Morgan. I used to put her in the pen every time i left the house and at night until she was 2 or 3 years old (can't really remember when i stopped doing it). She is 4 now and stays in my studio like room when i'm gone with access to her crate, my bed, her beds, and the couch. she pretty much can do whatever she wants while i'm gone, but i think she mostly sleeps. anyway, currently i only have the crate out and she'll go in there on her own to sleep if she wants. I now only make her go in it when i need to leave, and she won't poop outside even though i know she has to. i don't want to come home to poop on the floor so i tell her "kennel" and she goes in on her own then i shut the door. its for her own good and safety and my peace of mind.
I have seen a picture of the crate you are using and saw that she won't go in there voluntarily but will go in her ex-pen on her own. If the pen is wire and she likes it maybe you should get a wire crate. maybe she likes being able to see out at every angle. then you can get a crate with a divider and make it smaller if you have to for potty training purposes.
Since she's a houdini the only solutions are to put her in the bathroom with nothing she can destroy, get a wire ex-pen with a secure top, or just put her in the crate (wire or plastic) willingly or unwillingly before you leave.