First, congratulations on a great site but here are some shooting ideas:
1 The girl has come to have a diagphragm fitted. Maybe she can't take the Pill and her boyfriend won't use a condom, or maybe she gets very horny during her period and her boyfriend doesn't want to put his penis in her vagina when its bloody - anyway she has to use a diagphragm. This scene would involve the doctor showing her how to insert it, and then the girl inserting it under his instruction. An ex gf of mine used to insert her diaphragm standing with one foot on the floor and the other on the edge of the bath, an in that position you could get some good images looking upwards into the girls wide open labia. This might also be an opportunity to introduce a nurse, who demonstrates how she inserts a diaphragm in her own vagina and then instructs the patient.
2 The doctor has to measure the size of the girls vagina. This might be important because the girl works in porn and a recent scene with an exceptionally well endowed stud was very uncomfortable. So she needs advice on the size of penis that she can safely take. To measure her vagina the doctor tests her with a series of penis-shaped dildos: they are different girths (small to large) and the length is marked on the outside. They are inserted in turn, until a point of excessive discomfort is reached. This scene could also be done with the aid of a nurse. The nurse would be naked with a harness round her hips, and the different sized dildos would be attached to in turn - thus she could penetrate the patient and simulate actual sexual intercourse - this could be done in a variety of positions so that the patient understands the different effects with a penis of the same size.