Urgent funds needed for Partner Visa Campaign

My sister, Megan a South African and her husband, an Australian met online in the beginning of 2019, when our dad passed away in the middle of June, he made the leap to come to South Africa to meet Megan and give her support during one of the most difficult times of our lives, he stayed for a month and then went back home. When he wanted to visit again, covid had hit and the lockdowns kept them apart for 13 months. When borders opened, he came back to South Africa in October 2020, they got married 3 months later. Her husband lived with her for 2.5 years where he overstayed his visa and his visa extension unknowingly because the government kept extending visas and the last extension from the government wasn't clear, the extension from the government came about the same day he received his extension in which he had 1 day to try and leave the country, they did not realise the last government visa extension did not apply for him, it was not possible so he overstayed further to stay by her side. He has since gone back to Australia (unwillingly) for work in April 2023, which left him with a 5 year ban to South Africa. Megan has tried to get a visitor visa to Australia since he left and it was declined because of them being married and they didn't believe she would be a true visitor.

They've tried all avenues to get funds to start Megans partner visa process so they can reunite but they have all been dead ends and impossible tasks. This is causing stress on their marriage which is leading up to a likely divorce.