How do I log someone off my Facebook account?

[Kraig]

I logged onto facebook on my sisters phone. Shes sabotaging my account. How do i get her off without deactivating my account

[SwayzeWolverine]

When you log on change your password.

[BlackHills]

change your password then log off.. then log back in but don't save your password.

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in the settings, there's a button to clear every login information stored in every mobile devices you used to log in, so all you need is find that, click it, then wait.
you said sister? so if you have acess to her phone, just clear up the cookies from the browser you used.