Well, I'll say it for you wc (some anyhow).
Arabianequine, please do not think I am criticizing, I am trying to *help* -- please PLEASE do not get another horse until you have upgraded that fencing. The bare t-posts and barbwire are a tremendous risk for serious injury or even death -- especially if you put another horse in there too. (The pagewire mesh isn't the safest thing around horses either but isn't nearly as bad as the barbwire and t-posts in terms of how often it causes serious or fatal injury).
It would not cost that much to get a good fence charger and something electrifiable (for a small paddock like that I would recommend that at least the top strand be something reasonably visible, like 1/2" tape or electric rope; other lines can be something easily-breakable like 17 gauge aluminum wire, for more safety). A strand could be run on long standoff insulators inside of the pagewire, too, to reduce the risk of problems from horse+wire.
Yes, I know people sometimes get lucky with that kind of setup, sometimes for years. But when you're not extra-lucky, things can be REALLY gruesome (also expensive, and terribly painful for the horse, long-term). And given that the horse in question is a frisky bored 2 yr old Arab filly, that kind of raises the risk more.
Please, please put the horse shopping on hold while you remove the barbwire, cap the t-posts, and add electric?? I have just seen too many situations like that where the person stakes everything on being as lucky as the guy down the road... and then isn't.
If your filly has no grazing in there, she should be getting at least 10 lbs of hay a day but really preferably more like 20+ (free choice; doesn't need to be high-octane alfalfa hay, just 'decent' hay). I have no idea what weight flakes you're feeding, but if it's not approaching 20 lbs then that may be a PRIME cause of her misbehavior right there.
I know you are trying to do what's right -- that is evident from your very sensible approach to looking for a second horse, and going the extra mile to have a trainer work with you and your filly -- I am just trying to give you a heads-up to things you may not fully realize the consequences of.
Best of luck,
Pat