Unfortunately, while this is something that they’re looking into, there is currently no force logout of all devices. The standard timeout for password to be required is 7 days. You could try calling support at (844) 999-3226 and see if they can do so on the server end. I don’t know if that’s possible.
Other than that, other than waiting 7 days, I think the only option would be to create a new account using a different email address and set the cameras up on that account.
EDIT: I just realized you said “on the first”, so her login should time out by then and you should be good to go.