Could Samantha have been a 36 overbust and they used that # to make it sound like she's bigger?
No. It was in the days of the +4 measuring method - where you measured your underbust, rounded up and added four inches. So a 31” back became a 32” and you added 4” to make it a 36. It’s how bra sizes were determined from the 70s/80s into the mid-2000s, and how we ended up wearing 34 and 36DD bras (or XL if you were super-big) - which were all wrong.
So let’s assume Sam was a 31” back, you’d round that to 32” and add four inches to get a 36 back - and then DD cup was basically what she would have had to fit herself into.
To my mind, she’s probably a 30 back and possibly about 34-36” around the bust, which would give her something like a 30F in real money, but I’m not even convinced she was a 30F. I was a 30/32FF until recently (I’m now a 30GG) and I’m way bigger than she ever was.
She was probably something like a 28F, maybe a 30E.