Welcome Kellie : )
I’m not entirely sure if it would make her sick but with rabbits it’s better to not take the chance. You should be able to exchange the bag even if you’ve opened it. I think the saltiness of the soda would be tempting for a rabbit so yes, she may want to eat it. Just eating too much litter even without the soda could cause problems. If you can take it back, maybe you can fashion a screen to put over it in the litterbox until you’ve used it up.
From what I can tell Prairie is just the brand name not the type of hay? Anyway, timothy grass hay is a great hay for rabbits. Sometimes bagged hay can be dusty and unappealing but there are plenty of brands available. Or you can buy it in a small bale. I did just looked at some pictures of that brand and the hay in some looked suspiciously too green. Be aware that hay is sometimes coloured to make it look better. I might be mistaken as I did see other pics where the hay looked more regular.
Good green (Prairie Tim Hay pic below) Bad green?
(also Prairie Tim Hay pic)
