Will my python ever recover?

[Malum Argenteum]

She got the mites from some bedding I bought at petsmart. That's the only was she could have because she didn't have any when I first got her.

There's a good chance that those were harmless detrivorous mites. When I was a novice snake keeper, I had that mix up (figured it out before I started treating with anything, thankfully), and many new keepers of all sorts of herps misidentify the many ubiquitous and harmless critters as parasites.

Though this has been said in this thread more than a few times already, nothing about the situation as it has been described here looks like a reason for euthanasia. It looks like a slightly aged snake is slowing down, though a snake that is accepting prey as it is offered is a snake that hasn't slowed down much.

And for context, as a breeder I'm quite quick to euthanize herps I produced if they have malformations (though I have gifted some to someone I know who has a big heart and a lot of free time) or other conditions that would make them an unsuitable captive, or for genetic issues that I worry would be passed along in breeding. But animals that I have any sort of 'pet' attachment to (including some retired breeders) I treat like I would any pet: I see them through their whole lives, including the part at the end so long as they're not obviously in actual and non-negligible physical pain.