You can add categories. No permission necessary. But you do want to make certain your categories follow our naming and linking conventions so when in doubt is always good to come here and ask.
Before we work on your questions you need to know that we now discourage categorizing profiles in counties. It is much preferred that profiles reside in the smaller localities of cities, towns or villages. For example Martha's profile should not be categorized in the county of Franklin but in the city of Columbus, Ohio. That category is already a part of our category tree and we are adding new localities everyday. You will making a valuable contribution if you add any localities if they are not yet a part of our tree. So you will want to remove the county categories on Martha's profile and add the cities that were important to her history.
Back on topic... your category you made of
[[Category:1913 Columbus Ohio Flood]]
needs some tweaking. It is missing a Comma between "Columbus" and "Ohio". You need to remove that category from the profiles you have added it to. That will make the category you have made disappear from our "unsaved category" list.
Before we add a new category with the proper commas that let's look at the historical event that you are wanting to categorize. The 1913 flood was not only in Columbus but also in many other cities and remains Ohio's largest natural disaster. So perhaps a better title for the category would be
[[Category:1913 Ohio Flood]]
Once you add that new category in Martha's profile biography box and saved your work go to the public side of her profile. See how that category is in RED? That means it is a new category and hasn't yet been saved. You should never leave categories you make with red links because they are not part of our tree and can't be located by other users. So, click on that RED link.
You are now at a page that warns you that it is a Preview Page and has not yet been saved. This is your opportunity to link to the rest of our category tree. You do that in the textbook located on this page.
Rather than "Events" I would link this to
Since it played such an important part in the history of Columbus and Dayton, Ohio I would also link it to
I have checked and both of those cities have already been saved so you don't need to save them by adding them. Just put those three categories at the top of the textbox. It is important to remember that you are making your new category a subcategory of those three categories. Any categories added should always be larger than the category page on which you are working. The actual flood is only a small part of the history of Ohio and the cities of Dayton and Columbus.
Now comes the fun part. You can write a description of the flood and put in resource links about the flood in the textbox below the categories. For example see
to see how this can be done for an event.
Don't forget to save the category once you have finished adding the categories and information.
If you have any questions or if anything I've written is not clear... ask away!