Her degree is in journalism.
Rest assured she writes her own articles and columns.
Frankly, it's irrelevant. If she has one or more writers/editors helping her with these articles, it's still being done with her words and voice; the writers and/or editors would just be there to polish and package.
I mean, more power to her if she does this without any help, but there's no insult to her intelligence or ability to assume she might have assistance with the finished product.