This topic might have a better name.
If this definitely refers to the same character, shouldn't it be Tina (A Groatsworth of Wit)?
Talk about it here.
Tina was a cleaner that lived on the Powell Estate in London. (TV: The Christmas Invasion) When the two were children, Rose Tyler was jealous of Tina's Play-Doh Mop Top Hair Shop, and "stamped her foot" in response. (COMIC: A Groatsworth of Wit)
By Christmas 2006, she had a lodger who was a medical student. (TV: The Christmas Invasion)