Notification Bugs on Logged out Accounts on Twitter and Instagram

You see, I'm using the new Ipad which I bought last April. My sister likes to borrow it to play and post stuff using her twitter and Instagram account. Afterwards she would log-out her account.

The problem is, I would get notifications from HER account along with mine. At first I thought it was a bug that affects the Twitter app but soon I realized it was also affecting The Instagram app.

Is there a solution to this problem? Its very annoying to be honest.

P.S. : I did try to 'delete' her account on the settings App >Twitter Tab but I still get notifications from her account.