She also, whatever you think of her politics, was carving out an impressive place for herself at the Palace of Westminster.
Until yesterday that is, when she announced she was packing it all in to spend more time with her family.
Oooh. Ok then. What do we make of that?
A woman letting the sisterhood down because she didn't keep on matching down a road that might, possibly, perhaps make things better for the rest of us?
A guilt-wracked mother buckling under the weight of the cliches? Someone with a soon to be exposed and scandelous secret?
Or a wife who knows a transatlantic marriage would be a short one.
Perhaps simply another exhausted woman who said: "Bugger it, I can't do this any longer - it's impossible to keep everyone happy and be true to myself."
Unless we were there at the Mensch kitchen table while they debated whose job was most important, we have no way of being sure.
He is a New Yorker who manages rock bands including Metallica. Perhaps, at first, they thought they could manage on opposite sides of the Atlantic, or maybe Louise believed she could persuade her hubby to move east.
However, it's depressing that a woman who is fortunate enough to be able to afford all the advantages of money and class still can't find away through the job, love, motherhood maze. Especially as we all thought that financial independence was one of the keys to the solution.
Having made a very similar decision more than five years ago, I've watched with interest, and a nod of recognition. I was going to say that when I decided to step away from the full-time work world the stakes weren't so high, but that's not true. My family, marriage, mental health and well-being are just as valuable as Ms Mensch's.
It's less of another role model chucking in the towel and more of a recognition that Having It All is not possible and, furthermore, the whole deal just isn't fair.
So, Louise, one final plea before you go - talk about it. Loudly and in public; you're good at that. I know you keep your family life private, but this is bigger than that. Let's discuss the pressures, the expectations, and how we're going to resolve it all.
Surely there is a way to be successful and fulfilled without betraying our loved ones.
Louise, you've got a voice, please use it for the other women who understand how you feel.