To be more precise:
Your wife is correct that NO ONE was on-hand in real-time when Bill and Hillary made their ORIGINAL bargain.
But later, Hillary did call Bill’s mind back to their bargain IN WRITING, and the occasion was that early time just after they got married, when Bill had just begun to really cheat on Hillary on a pretty regular basis.
So there is evidence for their bargain.
Bill brings the charm and popularity.
Hillary cleans up the messes and instills discipline, a semblance of structure.
The conception of Chelsea was also a calculated part of the plan and the RUMOR is that Hillary did, in fact, become pregnant earlier, but with a boy and for some reason the pair had established that a girl instead would be “play better”, politically.
Chelsea owes her life to political advisers. I hope she sends them flowers on her birthday.