That connects to my thought of using flowers to cover the cam...that makes me think female, too.
That person is really bundled.....some postures say female, too.
Remember, Nancy is fragile and can't go far. I believe there's someone just out of camera range...i.e., there's at least two people involved. This is NOT a one man/woman job.
I think old nurses aid and dumb a** husband who is a techy.
I'd say there's a third person...in charge of the car.
And two places...one where the nurse is with Nancy and knows and has access to meds...and another place for the two other perps.
What was the motive?
I think you could be right.