Guided somebody else for the first time... she didn't like it!

I guided a friend of mine through the first meditation session. She's got hiatal hernia like me, meditation is pretty much required as the relaxing effect loosens the hiatus, allowing the stomach to drop into place, alleviating the symptoms.

The problem is she nearly lost it. She got terrified to the verge of panic and the only reason she lasted to the end was because she kind of forced it. She got afraid of the lack of control she had, and was really scared by her isolation from the world, even from her own body!

Now I'm not sure how to deal with her. Any suggestions?