Hi Roku,
I myself am a new guinea pig human but I think anybody on here will agree when I say, "Yes 100% get her a companion!" Guinea pigs are very social and bond deeply with one another in a way we as humans can not. They need that interaction, especially if you will be away a lot. Plus, watching them interact, cuddle, play, and talk to one another is hysterical and very therapeutic. I too travel back and forth currently for school and having two cages, if in your budget, most likely can't hurt..? (Everyone, feel free to correct me if I'm wrong.) If I were to have two separate cages, I would bring along familiar pigloos, toys, and items that will remind them of home as to make their transition each time as seamless and stress free as possible. I have the Midwest Guinea Pig Habitat which is sold on Amazon and plenty of other sites. It's extremely easy to set-up/take-down, clean, and connect to an array of other playpens etc. As for travel, I've read that hard-sided cat carriers with a top-loading feature is best.
Please heavily consider adopting two. If you're already committed to the idea of one, what's one more tiny guinea pig mouth to feed? Plus, then you'll have 2 cuddle buddies when you spend time relaxing at home. They'll appreciate the company and you will too. Good luck!