You may have to leash her at your side when you're walking the paths so you can guide her to a better place for elimination when she feels the urge, Floppy Dog. I'd treat it like I would potty training--interrupt an elimination in an inappropriate place and move to a better place to finish, then praise.
"We are--each of us--dying; it's how we live in the meantime that makes the difference."
"It's not what you gather, but what you scatter that tells what kind of life you have lived!"
"Be kinder than necessary, for everyone you meet is fighting some kind of battle."