If she is losing weight, then she is not eating as much hay as needed. Hay is 80% of their daily food intake and you cannot judge how much they are eating by eye. If hay intake drops, then they lose weight and you must step in and help.
I'm sorry you don’t have access to a vet, but there is a medical reason for her to be losing weight so seeing a vet is needed to find out why.
It’s essential you step in and syringe feed her a fibre rich recovery feed or mushed pellets to replace her reduced hay intake. The guide I linked in above explains how essential syringe feeding is if a piggy is not eating enough hay independently.
Please ensure you weigh her every day on normal kitchen scales. Weighing should be done every week as part of routine care, but it needs to be done daily when a piggy is unwell so you can be sure you are syringe feeding enough to stabilise and stop weight loss
Hay is the largest part of the diet, with veg being supplementary at one cup per pig per day.
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