Jason Summerfield's mother
From Tardis Wiki, the free Doctor Who reference
Jason Summerfield's mother gave birth to her son in 2007, having been impregnated by Benedict Summerfield I. Even though Benedict had left her long before Jason was born, she still decided to give Jason the last name "Summerfield".
Records of the birth survived until the 26th century. Christine Summerfield read about it in the Summerfield family tree. (PROSE: Dead Romance)