sooo..... crazy theory here

[JediKitteh]

i was walking home today after drinking my 4th monster and i thought of something. what if susan was jenny's daughter and wound up traveling with the 1st doctor because of timey wimey circumstances.

think about it...susan isnt really a time lordy name....

[Clare_N]

Well, we can be pretty certain that Susan adopted the name Foreman from the scrapyard where we first see the TARDIS, But, other than that, we don't know anything about the origins of her name. As for her being Jenny's daughter, there's a scene in "Fear Her" where the Doctor tells Rose: "I was a dad once." It's more likely that that's where Susan came from, though we don't know anything definite about who her parents were. However, there have been instances throughout the series of names being duplicated on different planets - it's possible that Susan could be one such name.