Unless someone who has had piggy ringworm tells you it is important to have this final bath I wouldn't bother. Her coat is looking in great condition - what a change from her earlier photos when she did look a poor little thing. And she might have a sensitive reaction to any shampoo or soap which could make her susceptible to ringworm again. What is that saying... "if it ain't broke, don't fix it"
I will admit I am sensitive about baths: I once lost an elderly piggy because of a bath. Her immune system was failing because of age and she got some sort of fungus on her skin - vet said not ringworm but some other fungus similar with itching and some hair loss all over the body but no obvious 'patches' or scabs. Her cage mates showed no symptoms. The treatment was three shampoos 2 weeks apart. My gentle girl looked great by the last treatment and just as I was trying to carefully wipe her face she gave a little sniff, a snort and a sneeze. She had inhaled a tiny drop of water - just clean water. She seemed fine as she was dried off - we were all happy the treatment had worked, but the next morning she looked a bit subdued and then she went downhill very fast. I rushed her to the vet in the afternoon but too late - vet said her lungs had filled with fluid and she died that evening. I broke my heart and vet was very kind saying that it might just be that she was too old to fight anything off but I still blame myself even now. It happened in a second and it is very hard to get over.