Lady Waltham is a villain in
The Legend of Tarzan.
She is an aristocratic lady and the sister of the deceased Clayton who wants revenge on Tarzan for killing her brother - at least, in her own mind. He had her valet Hobson capture those close to him and she then poisoned Tarzan. Tarzan was then given a challenge by Lady Waltham which was either save those he is close to from danger or head to a mountain she dubbed "Clayton's Peak" where the antidote is. Though Tarzan managed to save his friends and family, he then ended up saving Lady Waltham from leopards. Afterwards, she gave Tarzan the antidote knowing that Tarzan didn't "kill" her brother.