This is a possibility but remember Marilyn specifically said:
"I'm not hiring anyone today"
So how much longer would it have taken her to hire someone had Sam not stepped in and got Barbara hired that day?
Marilyn changed her mood more often than she changed her panties. Sometime that day she would have realised she needed a PA and hired someone.
On an entirely unrelated topic SBF, I clicked on the link in your siggie to try to see your screencap collection, but all there is is a picture of the Quantum Leap logo. Is there something else I have to do to see the screencaps?