Matilda of Flanders

MATHILDE de Flandre (-24 Jul, 995 or before). "Susanna regina cum filio suo Baldwino" donated "alodem suum…Atingehem…et in Testereph" to Saint-Pierre de Gand, for the soul of "filie sue Mathildis", by charter dated 26 Jun 995[188]. It is not known whether Mathilde was older or younger than her brother Baudouin but the estimated birth date range of their mother suggests that Baudouin may have been her younger child. The Memorial of "Mathildis filia…Arnulfi viri" records her death "IX Kal Aug"

Source: http://fmg.ac/Projects/MedLands/FLANDERS,%20HAINAUT.htm