Is she sitting looking into the corner & looking a bit fluffed up? That's often a sign a Guinea is feeling unwell, she really needs to see a vet if that's the case, it could be anything from a UTI, URI, pain, reproductive problem, abscess or dental issue, loneliness, the list goes on!
If you catch whatever it is early, the chances are she'll recover more quickly, before any illness takes hold or gets worse.
If you're a bit short of finances at the moment see if you have any decent PDSA vets near you - they will often treat animals for free or heavily discounted, especially if you're on certain benefits?
Try asking your regular vet (if you have one) if they can do a payment plan, to pay off a bit at a time if no PDSA ones available.
Its good that she's generally OK, eating, drinking, pooping, etc ok. Try weighing her daily for a while to try & establish if she's staying at a stable weight (give or take 50g for a full or empty bladder). Mush up some hot water & pellets to syringe feed, if she starts to lose more than 50g a day or loses it rapidly.
It'll probably be cheaper to get a vets appointment in surgery hours over the next day or two, than having to rush her in as an emergency at 'awkward o'clock' - like Guineas have a habit of doing!
Good luck in getting her an appointment - fingers & paws all crossed for a speedy recovery.
Let us know how she gets on xx
