Will she have pets or throw/area rugs? Those are the only reasons I can think of that would make me want one if I only had wood floors. I actually prefer sweeping our hard floors because the vacuum just tends to blow the dirt/cat hair around. She might also consider a small stick vacuum if she decides she really wants one, since they're fairly inexpensive.
I wouldn't use one at all. In her situation, any throw rugs I'd have could be shook out, or washed. Otherwise I'd use a Swiffer and if needed, cleaner.
If she has long hair and any type of,rug, she might need one. College roomie and I both had long hair and our little space rug looked so nasty in a week!
does her apartment have a washer/dryer? if so then I would vote 'yes' and get her one along with one of the inexpensive lint trap attachments. I'm dogged about cleaning out the lint trap after every load but it's amazing how much gets trapped out of reach.
I love it. I'd 100% have one in an apartment. It's so much quicker and actually sucks out the dirt/dust rather than pushing it around. Also great for food spills. I recently got a roomba so I only use this for spot cleaning and bathrooms but I'd never get rid of it. Does a nice job on area rugs as well. She'll likely want a few rugs somewhere in her apartment if it's all hardwood.
I agree with the stick vacuum that can be converted into a handheld. As PP mentioned there will be spills or things broken where a vacuum would be much more efficient. I use my DustBuster several times a day, everyday and I'm by no means a clean freak. It's great to hit corners where stuff tends to collect, I hit the bathroom with it, use it on my countertops before I wipe them down, vacuum the dust off the back of the tv and vacuum up the pile from sweeping. All sorts of things you never think about. Is it 100% needed? Probably not but it sure makes life a little bit easier.
I would check sales for a small stick/convertible vacuum. This type is on sale now, due to the "back to college" theme, so she could probably get one for ~$20. She doesn't need anything fancy, but might like to have something--DH likes to vacuum our hardwood floors (I prefer sweeping, but I'm not going to turn down help). The attachments are also good for edges, upholstery, etc.
I have one,b/c I have pets that shed! I have all wood floors with a couple of throw rugs which I shake out or wash as needed, sweep and swiffer just fine. The vacuum is mostly for the furniture,esp. in winter when they're all indoors hanging out in the livingroom!
I have had hardwood floors for years and it would not be without it. In my dorm I had a cheap stick vacuum. If she has longer hair it can accumulate in corners and under things. Dust clings to it and you then end up with "tumbleweeds" that would be hard to get with a swiffer cloth. I also use my vacuum to clean wood trim, top of baseboard heaters, and even lamps. Without one all that needs to be dusted.
I got my first vacuum at a biglots for cheap, it wasn't anything fancy but did the job. I bought a super cheap mop at walmart instead of swiffer cleaners as I found they are very pricey after a while, where a mop/bucket and vacuum can be cheaper in the long run.
Right after we moved to our current home , our vacuum died. We have all laminate and tile flooring and a handful of area rugs. I started using our garage shop vac "temporarily" for areas I would have used the regular vacuum. 6 years later I still haven't replaced our upright! For under $40 a small shop vac would work. AND it can be used to clean up wet messes/spills.