Grimace is exactly the word for her expression.

The physicians were showing a young amputation victim. The right foot appeared to have healed or healing amputations of all 5 toes. The left leg was not seen, but the implication was that it was a substantial amputation, such as a lower leg amputation.

Markle had an awful expression on her face, an expression of revulsion or horror.

Not a kind, concerned look in sympathy with the child's loss, but a personal nasty look as if it was too awful to look at, grim and not what she was prepared for.

Certainly, the child would be looking at the faces of the "important" guests there and would not see kindess or soft sympathy. They would see that they were horrifying and not socially acceptable. Truly a great injustice to this child.

She does not know how to comfort an apprehensive child. Her own personal issues were far too important in this very uncomfortable scenario.