I'm sure it was more an information type letter, rather than directly asking, or maybe asking your wife to consider making provision for a gift to PUK in her will. I am assuming that your wife is a member of PUK and therefore that this was not unsolicited mail.
If they don't ask, they don't get. We have already done this and our daughter has today posted off asking for information regarding a legacy in her will.
Surprised that Admin. has not responded to your comment.... yet!