Shared anything is always a road to a gunfight in this USA.
You should have sat on down with her and have had two or three options other than a ratty fence. Did you really want to piss her off?
Is it too late or have you two destroyed all communications by both acting a little childish.
Why would you fence off her property with crappy woad showing on her living side?
I would have considered a bigass planter with climbing things like Manevilia or red flags to attract hummingbirds. Or several potted cedar trees in a line.(They grow your and her privacy with some nic plants.
Surprised you didnt consider a porch garden to share some veggie growing .
Why cant she paint it without your permission?? I dont unerstand your sene of entitlement. You put the thing up without even talking to her. I assume its on her line so I hope she says"why do you have the right to deny me my right to paint it?".