The following is from a Telegraph article "Here's why I'll be giving the no make-up selfie a miss".
More than that, why should anyone dictate that looking as stripped as Shaker furniture is the predetermined lot of the cancer patient? As it happens, my friend and I share a firm belief in the alchemical properties of quality maquillage. Chanel Rouge lipstick and Clinique foundation have proved as important for her morale as chemo has been for her recovery. Only yesterday her radiographer told her she couldn't possibly be old enough to have a daughter in her twenties.
As I understand it, the last sentence means that never before yesterday did her radiographer tell her she couldn't possibly be old enough to have a daughter in her twenties.
If my understanding is correct, "only yesterday" has a negative meaning that affects the following clause. And I wonder why the reporter didn't invert the order and say "Only yesterday did her radiographer tell her she couldn't possibly be old enough to have a daughter in her twenties."?
Is the inversion allowed here?
If so, is the inversion optional as opposed to mandatory?