Why should having it all mean having a full time job?
Having it all means different things to different people.
By working part time, I have more time to persue research interests, and hobbies.
Having it all for me means attaining a situation where you are fulfilled, for some that might mean career with nanny, for me that would leave me dissatisfied, therefore I would not feel I have it all.
I am often asks why I don't go for promotion. I am not mad, but have a good work life balance what suits me.