This is the only Mathilde of Sponheim I can find, & she doesn't look like the same person at all:
"Matilda of Carinthia or Mathilde of Sponheim (died 13 December 1160 or 1161) was the daughter of Engelbert, Duke of Carinthia[1] and his wife Uta of Passau. She married Theobald II, Count of Champagne[2] in 1123.[3] She was the mother of Adèle of Champagne, Queen of France and thus the maternal grandmother of Philip II of France. " http://en.wikipedia.org/wiki/Matilda_of_Carinthia