Ellen, on the left side of the page for the image which you want to add a photo in the bio, there is a list of codes you can use to place it where you want (centered, right...). Copy the code into the bio where you want it and save.
For example, for my great-grandfather I see this code on one of his photos for centering the photo in the bio:
|caption=Tom Shepherd on his farm.
For putting on the right side in the text box, I have this:
|caption=Here's an image.
Notice there's a place for you to add a caption if you wish.