Individual Details

According to Wikipedia:

Rixa of Werle (died 26 November 1317) was the only daughter of Lord Henry I of Werle and his wife Rikissa Birgersdotter. Rikissa was a daughter of Birger Magnusson of Bjälbo and his first wife Ingeborg.
Rixa of Werle married on 10 January 1284 with Duke Albert II, Duke of Brunswick-Lüneburg.
They had 11 children:
Luther (died: c.  1334), joined the Teutonic Order
Bruno (died: 31 August 1303)
Adelaide (died: c. 1311), married John, Landgrave of Lower Hesse
Maud (died: 1 January 1356)
Otto, Duke of Brunswick-Lüneburg (born: 24 January 1292 – died: 30 August 1344)
Albert II (born: c.  1294 – died: 13 October 1359), bishop of Halberstadt
William (born: c.  1295 – died: 1318)
Henry III (born: c.  1296 – died: 6 February 1363), bishop of Hildesheim
Richenza (born: c.  1298 – died: 26 April 1317), abbess of Gandersheim Abbey
Magnus, Duke of Brunswick-Wolfenbüttel (born: c.  1304 – died: July 1369)
Ernest, Duke of Brunswick-Göttingen (born: c.  1305 – died: 24 April 1367)

Marriage	10 Jan 1284	Albert II "the Fat," Duke of Brunswick-Lüneburg
Death	26 Nov 1317

Spouse	Albert II "the Fat," Duke of Brunswick-Lüneburg (1268 - 1318)
Child	Magnus I "the Pious," Duke of Brunswick-Lüneburg (1304 - 1369)

Father	Henry I, Prince of Werle ( - 1291)
Mother	Rikissa Birgersdotter (1237 - 1288)