DD's registrar is a female doctor about the same age as her and the two of them get on like a house on fire, probably the shared Irish genes, (or is that racist!). She described DD as this 'delightful lady' in a letter to her GP so I do not see how the phrase, certainly in her case, can be either sexist or condescending.
DD gets a copy of every letter sent out to her GP or anyone else involved in her treatment, including internal memos (as we used to say) from the doctor who sees her in the clinic to the consultant when, as this week, there was a detailed discussion about the options for the next stage of her treatment.
I suspect that now that patients can see all their notes doctors have reversed the system 'delightful lady' means a patient we can work with 'this lady' means a bit difficult to deal with and 'this patient' means really diificult, doesnt take medication regularly and ignores our advice.