There is no such thing as a complete healthy human being. We all have issues, of some sort or another, varying in intensity from mild to severe.
Even young children are afflicted with something or other. For example, it is not uncommon for kids to have ear infections or to suffer the flu.
Teens might struggle with bladder infections, cramps or the common cold.
Then there are sprains, strains and broken bones.
As we age, we run into even more difficulties. We might need glasses or hearing aids. We might have difficulty swallowing or lose some degree of balance.
The challenge this week is to write a story/scene in which your protagonist has some type of health issue. Before you write, think about how it affects his/her life. Does it mean sitting in the front row in a classroom? Walking with a cane? Using a walker or wheelchair?
There needs to be conflict to make the story interesting, so use the health issue as an impetus for the conflict. Perhaps people get tired of shouting to be heard or maybe the character is color blind and so runs a red light.
Your task, then, is to add complexity to your character. Make her real, dealing with actual issues that all of us struggle with at one time or another.
Good luck with this one.