You can read Claire's reasons for leaving Google in her own words here: https://medium.com/@GoogleWalkout/why-a-googlewalkout-organi...
"I made the choice after the heads of my department branded me with a kind of scarlet letter that makes it difficult to do my job or find another one. If I stayed, I didn’t just worry that there’d be more public flogging, shunning, and stress, I expected it."
... are the next two sentences, and sounds like this weighed on her just as heavily as a pending childbirth.