If you make your freespace pages into subcategories instead, then any profile on which you put the subcategory will show up inside the group you have placed on your category page. (This is how you include any profile in any category in your Name Study.) For instance,
[[Category:Australia, Christopher Name Study]] and
[[Category:Iowa, Christopher Name Study]]
To learn how to nest categories, why not go back to the ONS Project page, where it tells you how step-by-step.
https://www.wikitree.com/wiki/Project:One_Name_Studies#Categorization
The profiles to which I was referring were all the profiles you have linked into your Christopher Name Study. You know, like Ada Pearl (Christopher) Nowlin, and Orin Sidney Christopher, or Fred Rayfield Christopher. You have put them in your Name Study by adding [[Category:Christopher Name Study]] to their profiles. You can see them all if you scroll down to the bottom of the page and click on 'Christopher Name Study' - that is your Category page. If, just say, you wanted to group all of the profiles that were born in Oklahoma, you would create [[Category:Oklahoma, Christopher Name Study]] and add that category to the profiles. I have done one for you, so you can see what it looks like (I chose Ada Pearl). Can you see just how useful this could be? These subcategories could be more useful than freespace pages.
Take a look at my Haywood Name Study (remember, scroll right down to the bottom and find the category 'Haywood Name Study' and then click on that) and see how I have used subcategories to group profiles.
https://www.wikitree.com/wiki/Space:Haywood_Name_Study