Seems to me like your "Fighter" wants to be a Rogue.
She's got a Dex of 18, Masterwork thieves tools, boots AND cloak of elvenkind, and ranks in Use Magic Device.
I'd consider doing a couple of things.
First and foremost, I would consider allowing her to be a gestalt Fighter/Rogue. Essentially, she advances in both classes at once -- she gets the best benefit of all things class-related each time she levels.
In the F/R case, she would get the Ftr HD, BAB, Fort save and feat progression. From the Rogue, she would get the better Ref save, skill points, and access to all Rogue skills as class instead of cross-class skills. All class abilities are gained at once, though the only class ability fighters get is feats.
F/R's rock. I'm playing a non-gestalt F/R and am getting lots of mileage out of him.
Another thing to try is allowing her to be the "boss" of a few supporting NPC's. This comes from the old school D&D days of needing 9 henchmen to follow you into a dungeon to spring traps and absorb hits for you. *G* I'd add from one to three NPC followers to assist her, guide her, be her best friend etc.
Or, you could just give her an item to up her Will save and let the dice fall where they may. *LOL*