The thing about antibiotics is that lab work must be done first so you know that you're using a drug that will be effective. Frankly, this snake doesn't have TIME for you
to experiment if you want her to live, and it's a very bad thing to use antibiotics improperly as that's how we end up with untreatably-resistant 'germs'. I agree with the
other posts- if you cannot get proper medical help now for this snake, you should immediately surrender her to a rescue that can and will do the right things to try to save her.