Travel and Class Pet

Question
I just recently bought a female guinea pig from a local pet store. She is young a baby but I have no other information about how old she may be.
She is a very calm little one doesn't complain about anything.
I take her to and from my work at a preschool she stays in the classroom and then I bring her home at night in a travel pet carrier.
I am just wondering how guinea pigs handle traveling to and from one cage to another she is also handled a lot which she doesn't seem to mind. She loves being held and lifts her head and sniffs people who are near she doesn't complain or whine at all.
Is this something that is safe and what do I need to know about traveling with a guinea pig? She just sits in the carrier and isn't noisy at all until we walk in the door then she squeaks until we get to the cage then she gets her hay.
I don't know a lot but I want to make sure she isn't stressed by going to and from.
Also are guinea pigs supposed to drink bottle water?
And she doesn't seem to eat any treats. Is this something good or bad?

Answer
My guinea pigs are therapy animals @ my school.  They are handled all the time. Not only do they ride in the car, but
they take the Metro as well.  Your piggie sounds wonderful for your students.  

I would not worry about treats from the pet store, just make sure she gets fruits and veggies.  Let the kids feed her.  

I give mine tap water, but then again, I have a herd of piggies.  Unless the water in your area is poor, tap water will do just fine.  

Thank you for being brave enough to have a piggie in class.  You may want to look into skinny pigs (hairless) as they adore interacting with people.  
Please stay in touch!
Bravo, Cindy