Well, first of all, Anne Marie Calvert is listed as his mother, not his wife. But the fact of the matter is that there is no documentation supporting the names of any parents of Colonel Ninian Beall.
Then why are they there? I contributed a substantial amount of the narrative to Ninian's biography. What I was NOT able to contribute was any documentation that his parents were NOT a James Beall and an Anne Marie Calvert. So I labelled the relationship questionable. That was as far as I felt able to go.
Even if no information is ever found as to who Ninian's parents are, there is another line of approach -- finding out more information about his alleged parents. Did James Beall exist? Was there ever an Anne Marie Calvert? And if they are real people, is there a record of what children they had? Perhaps they had a child named Ninian. Or perhaps they had a will that names 16 children, NONE of them named Ninian. All of that would help.
I personally try to be conservative in the changes I make on WikiTree. If I add something, I prefer to have a reason for doing it -- and if I subtract something, I want to be able to justify it. So I never would have added those names if I were creating the profile -- but I'm not the profile manager and I don't yet feel comfortable in subtracting those names.
But you are absolutely right in that their existence as relatives of Colonel Ninian Beall should be questioned. And hopefully more documentation will be found!