Chowing down on the nurse while she is still groggy from reforming looks like the best way to get a good lead, and to get a good meal. But you don't know much about reforming... Say, why not ask the nurse?

Pretend a little academic interest and she proves eager to explain every thing to you. More than you want, really. But she does confirm, without knowing your plot, that you can digest her and be able to swallow her again before she is active. So time to start digesting her, an idea she does not approve of.

The room is a bit cool and so you put on a lab robe as you pleasantly wait for the nurse to be fully digested. As you do, the door opens and a hot little redhead comes into the office, a bit timidly. "I'm candy, a new student. I was told to come to the nurse's office. Is she in?"

The lass has a quite attractive rack and will make a great meal, so you want to get close enough to her to attack, and the obvious way to do that is to pretend to be the acting nurse... "She is .. unavailable at the moment. I'm Rick, her assail..er assistant. I should be able to take care of you." Not in the way she has in mind most likely of course..
"Now let's see.." Grabbing the nurse's clipboard, you pretend to be looking for her name, and are surprised to find it. Making a check next to it, you turn to her and say "Now you need to take the potion 1st. Here you go. Just chug it. It's not the best tasting stuff." Thankfully you had spotted a rack of a couple of dozen potions.
She takes your advice and is ready for the next step. "Now we need to fill out some paperwork and give you a physical. You can use the screen there if you are feeling shy."

She hesitates. "Shouldn't I wait for the nurse?"

"When one is in medicine, one quickly learns to ignore the technical nudity." Of course, you are not in medicine, but with the nurse bloating your belly, nobody can see if you are at full attention.

"Well, ok.." and she darts behind the screen to strip while you fill out a little of the paperwork.

When she returns, making quite futile efforts to shield that lovely body, you order her onto the examining table, where she will be helpless. Instead, she claims "I don't really belong here."