https://en.m.wikipedia.org/wiki/Just_Stop_Oil

https://www.theguardian.com/environment/2022/apr/10/just-stop-oil-behind-the-scenes-with-the-activists

I can't find any evidence that they were founded by her but she did help found the climate action fund which has donated a large amount of money to them as well as Extinction Rebellion

https://en.m.wikipedia.org/wiki/Aileen_Getty

https://en.m.wikipedia.org/wiki/Climate_Emergency_Fund

I think she's probably genuine but that's also besides the point. Whether she has alternative motives or not all that really matters is whether the activism is helping or hurting