Should Women Keep a Secret Money Stash?

My grandmother surprised me recently when she suggested that I keep a secret stash of money, separate from my husband's and my shared account, for "emergencies." Not to sound naive, but I wasn't sure why I would need such a thing. Even in the worst-case scenario, aren't wives still entitled to half of all their joint accounts? My grandmother explained that it was just nice to have some flexibility—not to guard against disaster but in case I wanted to buy something on my own one day.

She's not the first grandmother to make such a suggestion. In Money: A Memoir, Liz Perle writes:

My grandmother went over to her pocketbook, a black patent leather rectangle with a silver clasp that I liked to snap open and shut. She removed a $20 bill, folded it twice, and stuck it into the bizarre purse, which she then handed to me.

"This is the beginning of your knipple," she said, pronouncing this alien word "kah-nipple." "It's a woman's private stash. Every woman needs one. A just-in-case account. Every woman needs money of her own that her husband never knows about. So she can do what she wants. What she needs. Remember that."

I'd love to hear any reader opinions on this one!