Aunt

An aunt or auntie were names used to describe a female relative who was either the sister of a parent, or an individual who was married to the sibling of a parent. An individual who has an aunt would be the aunt's niece or nephew.

Lavinia Smith was the aunt of Sarah Jane Smith. (TV: The Time Warrior) Due to the death of Sarah Jane's parents, Lavinia raised her from infancy. (PROSE: Playtime, TV: The Temptation of Sarah Jane Smith, The Day of the Clown)

As her parents were lost, Amy Pond was raised by her aunt Sharon. (TV: The Eleventh Hour, The Big Bang)

The often referred to herself as "Aunty Iris". (AUDIO: Iris Wildthyme Speaks...!, et al.)

Tegan Jovanka's Auntie Vanessa was murdered by. (TV: Logopolis)

Other references
Alongside Uncle and Nephew, Auntie was a servant of House (TV: The Doctor's Wife)

Auntie was the leader of a human colony in the 29th century. (AUDIO: Three's a Crowd)

"Aunty Winnie" was "the most famous children's author in the world". (PROSE: Hello Children, Everywhere)

While pretending to be the eccentric "Razor", once told Bill Potts that she was "like a mother to him". When Bill expressed discomfort with the comparison (as Razor was visibly significantly older than her), Razor amended his statement to her being an "aunt" to him, to further awkwardness. (TV: World Enough and Time)