Doctor Who is to get a Buffy-style sidekick when he makes his TV return. His new colleague will be a modern action heroine, according to writer Russell T Davies, who is reviving the sci-fi series for the BBC in 2005.
—Buffy ‘inspires Doctor sidekick’ (BBC)

While the screaming girly female companion is part of the Dr. Who lore, there were several notable exceptions, including Leela (my wife’s favorite) in the late 70s, who was very much a Xena/Buffy/Lara Croft type.