Thank you for reading the biography! Actually, the biography only covers the siblings of Giles Brent who interacted with him later in life when he was in Maryland. Anne Brent, who died never having married, is shown in the data field as one of Giles' sisters, and she has her own profile.
As Lord Proprietor of the Province of Maryland, Calvert's biography has been extensively studied, and no record identifying his wife has yet been found.
As is often the case, Ancestry, Find-a-Grave, and other popular genealogy sources are wrong.