Using oil does not mean approving of everything oil companies do. Especially when there are not alternatives for things like flying.

"Being an oil company" is not necessarily an inherently bad thing. Being one of the major oil companies in 2019 is -- but that will, hopefully, change.

I know people who have given up flying for this very reason. She could have chosen not to go and to conduct any business over the internet (I'm assuming she was flying for business and not for pleasure).