I need to point out that my issue is not that the author said something offensive. I do not endorse her comments in any way.
My issue is that she voiced a political opinion, something protected, and then a mob came after her livelihood and made it more difficult for her to earn an income.
You have the right to be offended, but your offence should not be used as a cudgel. You do NOT fight offensive speech by removing the speaker's income. You combat it by pointing it out and exposing it. Bad speech is best dealt with by using Good speech to expose it. You don't buy her books, but you don't take away that option from others simply because you don't like something the author said on social media.
I am a free speech absolutist. I believe EVERYONE deserves the right to say anything they want without fear of persecution. Attacking someone's livelihood because of something they said on social media is persecution.