As the lead of the US Presidents project, I have read through all of the comments and data on the "unknown" profile and the supposed parents. This is the reason that we project protect profiles, and we discuss findings within the project.
While there is a proposed article in the NGS Quarterly, Vol. 109, No. 4, December 2021: "Correct Interpretation of an Eighteenth-Century Virginia Will Restores the Parents of Allerton Newton of Westmoreland Count, Virginia" by Barbara Vines Little, that determines Mary was a daughter of Isaac and Elizabeth Willoughby. No one on the project has indicated that they have read the article and agrees with the article. Also, the Mayflower project was also asked to weigh in. Until we have a summary of the information from this article, the parents should not be added, although she was added to her father as the result of a merge.
Once we have the data and corrected information, we need to update the father's profile and the mother's profile with this information, as both profiles still indicate that Mary is not proven to be their daughter.