https://genfiles.com/articles/orphans-guardians/
For most of history an orphan was a fatherless child, irrespective of whether the mother was living. A child living with his mother and stepfather was an orphan in the eyes of the courts and the law. …
… Some children had their guardians determined by their father before his death. A father could appoint a guardian for his minor children in his will, although it is relatively unusual to find a will that explicitly does so. (A will could also eliminate the need for a guardian by declaring a minor child to be “free”, an even rarer occurrence.) On the other hand, many wills make the implicit assumption that the mother would act as the guardian by leaving a life estate to the widow, with possession to the child at majority. In effect, this made the mother the guardian by eliminating, or at least reducing, the need for a separate financial overseer of the child’s interest. …
Blackstone devotes an entire chapter to the subject of guardianship, covering several details not addressed above. See Sir William Blackstone’s Commentaries on the Laws of England (1765-1769), Book I, Chapter 17: “Of Guardian and Ward”.
Several of the earliest laws of Virginia dealt with orphans, their guardians, and estates. See William Waller Hening, Statutes at Large…, 1:261 (1643), 1:269-70 (1642), 1:416-7 (1656), 1: 443 (1657), 2:93-6 (1662), and 2:295-6 (1672). Largely restated in the legislature’s consolidations of 1705 [Hening 3:pp375], these statutes remained essentially unchanged through the end of the 18th century.
In other words, if the child had a living mother who had not remarried, there would be no reason for a curator or curatrix.