Ultimately it appears then to be your parents decision.
I would like to ask everyone to please calm down a little here and appreciate the fact that
@NKgirl2002 is trying to get this sorted out by coming on here for advice. In an ideal world we would all have access to a vet a short distance away and would equally have access to transport 24/7, and have the spare cash at our disposal to sort emergencies, and be able to drop everything and go. I know for a fact that there are members of this forum who must rely on their parents to get them to vets and to pay the initial cost. I would like you all to imagine please of being in the position of having to rely on someone else, and that person cannot or will not help you out.
@NKgirl2002 I am assuming by the timing of your posts that you are not from the UK. If you were it is highly likely that you could get you friend's piggy to the vet by taxi for around £10-£20 in most cases, even if it's not the best of vets. We are so built-up in most places in the UK that there's usually one not too far away. When we see an animal in a state of pain and stress who clearly requires prompt vet treatment it is upsetting for us and it's all too easy to judge people for not doing so, especially as, like I say, a visit to the vet is usually easier for us.
I am guessing you are from the USA. If you would like to give us your approximate location we should be able to look up your nearest recommended vet from where you live or from where your friend lives if it comes to that.
However it seems you are now in a tricky situation. That is a nasty infection. Your friend's piggy really does need to be seen sooner than Tuesday, but I actually do appreciate that it may be very difficult to achieve this with no access to transport.
In my own mind all sorts of solutions are running through, such as 'call a vet to make a home visit', and 'can't your mother take your sister with you to the vets' but ultimately we are left guessing at your circumstances here and only you know the reality.