Finding an agent is definitely preferable, especially if you can find an agent/real estate group that specializes in rentals over buying. This is certainly true if you're looking for rental houses over townhouses, condos, and apartments.
I'm in the process of moving my family from Pittsburgh to Cleveland. In the past, I always searched all of the rental sites (Zillow, HotPads, Craigslist, etc.) and set up showings by myself. If you're moving across town that might be fine, but if you're moving quite a distance, which I assume Sacramento is for your daughter, then having an agent with connections is so much more helpful and practical.
For example, with our busy schedules, we were only able to go to Cleveland for one day to look for houses last week. The agent that I'm working with is excellent, because not only did he compile a list of approximately 40 properties to choose showings from, we saw 8 different properties in the span of three to four hours that day. And he has done all of the legwork with contacting the other agents or landlords for questions and showings schedules, and the best part is that he's paid by the landlord, not us. So this is essentially a free, extensive service that we couldn't have done without. There's no way we could've seen the number of quality properties on our own.
So I'd definitely recommend Googling to find an agent or real estate group in the area that you could work with to find a good property for your daughter, especially if you're relocating across the country.