In the
popular TV show "The Weakest Link" contestants have an opportunity to "
bank" if they want to safehouse themselves from a future
mistake. This inspires the term "banking" to describe women of a certain age (generally 33+) settling, or "banking" on a perhaps unsuitable partner in order to leave appropriate time for marriage and babies.
"Why is
Jenny with that guy? He's an idiot"
"Oh,
well she's 33 now and she wants to
get married so she's banking"