ah you are australian...well I can help more now. There is a product called white healer. If its scabbed over as you say then this will really speed the healing process and help deal with any infections which it sounds like she has considering the red skin around the wound
I wouldnt ride her until all her sores have healed. Even then you may have to watch for more girth sores. If she gets sores a lot you can get lambs wool covers for girths to stop rubbing or an anti-gall girth from wintec I think
Ok I will look around for white healer. I have an anti-gall girth now, but Im selling that saddle so I will keep in mind about that. Thanks for your advice!