She certainly wasn't offering herself to me, if that's what you're suggesting. I never thought that for a moment.

I took it to mean, "What do you imagine it would be like if we were lovers."

Perhaps she is used to a lot of erotic transference from her male patients and was puzzled because she wasn't getting that from me?

Conversely, maybe she was concerned at my unswerving parental attachment and wanted me to consider the other possibilities. This could be the answer, in fact.

RECONSTRUCTION:

"You see me as your mother but you haven't explored the other kinds of relationship we might have. What if we were lovers?"