Rian ~
Yep, my Avatar is me. Fortunately, the leading U.S. Sex Change Clinic is just south of Denver CO. Obviously, they work wonders there!
If You're Looking Bad, Try Trinidad
As was my situation with my sotted p/t Neighbor, this really isn't about a Gate. It's about the need for control; a very different topic that 'mechanical' Gate implementations can only work around, at best.
After one Survey using 5 GPS Satellites referencing, which put the known Property Boundaries to within 'a few hundredths of an inch', I patiently pointed this out to my Neighbor as he screamed at me, Neck Veins bulging. Fortunately, I don't Smoke. Otherwise, his Alcohol-laden breath would have blown us both to Kingdom Come. His screaming response: 'It doesn't f--king matter where the Property Lines are'! That's about the time I gave up on 'rationality'. Patience beyond that point doesn't make him out the Fool. It makes me out the Fool, for continuing useless 'reasonable-ness' in my approach.
Your Concrete RR Ties over there, and some scrap, cast-off Steel, etc., would be a good, free start to a n/c Cattle Guard installation. The Neighbor will hate ANY pragmatic solution, I predict, because such solutions don't acknowledge her 'superiority', and they marginalize/work around her need for absolute control. This sort of intelligent Gate solution infuriates such 'Control Freak' folks even more. O'Well, as my fav Irish surname goes...
I've used, and still have, Electric Fence Chargers on several Gates at a Mountain House where there's House-invading Bears. I put some Black Foam Insulation, used on Hot Water Pipes, on one Gate Handle so that I can touch it in even wet Weather w/o shock. Old Washing Machine Hose pieces work well, too.
Cruise your lovely Countryside there to see how Rural Folks implement practical solutions to Animal Control, and peaceably share split Driveways to 'Divided Estates'. Even before I permanently acquired and annexed our Driveway, U.S. Easement Law dictated that we, the far-end Landowner, enjoyed the 'Superior' Rights. This is because we have only the one way in to our Property. However, enforcing that Law 24/7 is impossible with a devious Neighbor. This is why I circumvented our Court System to solve the issue a different way: outright ownership of our Access.
Being an Audio 'Nut', I would treat such a difficult Neighbor to Wall-shaking, Bass-laden Rap Music for 10 minute bursts every mid-night using a kiloWatt Amp I built. Everyone can be 'persuaded' into the desired behavior. Some folks simply take longer than others...
Good luck to your Pal...