It really depends on how much appreciation your significant other has for flashlights, not to say give her a lemon because she doesn't know any better, but you've got to be realistic. Outfitting someone with quality gear, who is not going to be impressed or appreciative of the quality is a lost cause. If I gave my girlfriend a SureFire (any model) she'd more likely impress someone else who saw it, than be impressed herself...she's a total non-flashoholic.
I gave her a AAA Mini Maglite (red) and she loves it. She keeps it by her bed at all times should she need to go about at night or whatnot. It's a stock light, and really she wouldn't want anything more, it lights up...which is all she cares about.
As far as suggestions, it also depends on where the light is going, keychain? Purse?
For a keychain, I'd say PT Pulsar II, or Eclipse II. Dorcy AAA LED would be good too, or a Dorcy "excell" AAA (available in pink!). A PT Blast is bigger, but a lot brighter than the others, maybe it's more of a purse light though.
A Gerber Infinity Ultra would be at home either on keys (you'd need to supply your own lanyard and ring) or in a purse, and would be sturdy and bright enough for the expected purpose. Plus it has the advantage of using a step-up regulator over my previous suggestions.
Pelican and Underwater Kinetics (UK) also make some small penlights that are good quality. Like the UK
UK2AAA eLED MPL or Pelican MightyLite.
I'd stick with an LED (not Luxeon) if possible as they'd last longer without battery changes. Speaking of batteries, I'd also stick with AAA or AA as they are easy to find, and are cheap. My girlfriend would probably just go without a flashlight (!!) if she tried shopping for 123 Lithium cells at the nearest hardware store. She'd probably see ordering online as too much trouble too, so I'd personally stick with what's readily available pretty much anywhere.
All round, I'd say the Gerber Infinity Ultra would be a good balance of cost, presentation, durability, runtime and brightness for a non-flasholholic who just wants a small light they can chuck in a purse or dangle from a key fob.