I'm sorry for your loss.
Next time, please take your pig(s) to a
cavy savvy vet as soon as you notice something is a miss. Guinea pigs tend to mask their symptoms, and as soon as one notices, the guinea pig could be sick for weeks. Personally, I would have took her to the vet as soon as she started to refuse her favorite vegetables.
With your next pig(s) make sure to weigh them weekly, as weight loss is the first sign of a problem. If a guinea pig loses 3 to 4 ounces in one week, the pig needs to go to the vet ASAP.