Sophie Welf von Bayern und Sachsen was born circa 1117 to Heinrich IX. von Bayern (1075-1126) and Wulfhild von Sachsen (c1075-1126) and died circa 1145 of unspecified causes. She married Berthold III. von Zähringen (c1085-1122) .
Children
| Name | Birth | Death | Joined with |
| Elisabeth von Steiermark (c1124-aft1138) | 1124 Steyr | 1138 | Rudolf II. von Stade (c1102-1144) Heinrich von Kärnten (-1161) |
| Otakar III. von Steiermark (c1125-1164) | |||
| Margaretha von Steiermark (-aft1138) | |||
| Kunigunde von Steiermark (-1177) | |||