Mitchell Baker is paid by the Mozilla Corporation which in turn is paid by it's search deals. She is paid $0 by the Mozilla Foundation and it's donations. Feel free to checkout the foundation financial statement from 2018 (it's on page 7):
Which in the context of how Mozilla deals with donations is a separate and unrelated discussion.
edit: More broadly, pointing out someone as making a false statement does not mean you agree with the opposite view, simply that you don't like people spreading false statements.
Sure, you were right to point out that freshsqueeze was incorrect in saying they funnel donations to their overpaid CEO, but the fungibility point is an important one.
A related point on fungibility turned up in earlier discussions: donating directly to Firefox might not count for much if Mozilla balance it out by redirecting the same sum of their general fund away from Firefox. [0][1]