As others have said time is dependent on how detailed birth parties are and what the scene is going to ultimately include.
For a true medfet exam I typically spend 45-60 minutes for a new patient and about 30 minutes for someone I have played with before...I find that the chat/play time online is longer because communication (typing and responding is slower)....I’ve found that throwing in the link(s) to a picture or two helps make things clearer and save lots of typing/or lack of a good description. I do like to set expectations of how long things will go so we don’t end up missing work, or dinner...
To ride my hobby-horse for a moment, I have hugely enjoyed intereactive medical exams by correspondence in which a knowledgeable (and resourceful) doctor thoroughly examines my alter ego, young Ken. One glorious Australian summer, a very proficient (and specialist) 'Dr Michael' of Melbourne conducted such an exam, and it must have lasted 2-3 weeks! Unforgettable! More details on request!- Ken
I don't recall a full exam lasting less than an hour unless my own time constraint limited me to just breast and pelvic.