I have feeling that she just “made it up”, and her real concern was related to the resurgence of (actual) leftist thoughts in the mainstream and she doesn’t want to pay any taxes. Since some segments no longer saw her as a “successful woman”, but as the same as her fellow millionaires but a woman, she looked for some exit plan.

Source: her early anti-Corbyn stances.

If you ask: people can gaslight themselves into believing dumb things, so as she submerged herself into the depths TERFdom, she slowly started to believe it herself for real this time.