I used to share my account with my sister. I logged her out and switched to Disney bundle and changed password. Someone keeps watching my account and I think it’s her. It says I’m only logged into my 2 devices. How can I figure out where I’m all logged in? My son uses it but has his own profile but it’s someone watching mine. His device is not showing up on my logged in devices

Edit: I’m just assuming it’s her based on the content watched and the fact that she was the only one with the password. In February I noticed it logged everyone out, changed password and switched from Hulu to Disney Bundle. I noticed it last few weeks so yesterday I got onto Hulu and only two devices are our TVs. I asked my son he said he wasn’t even home. It had me log out of Disney Bundle and logged me out of all devices. It kicked me off the two TVs but when I went to log in it didn’t use yesterday’s password it used the February password I created. Is there any other reason shows would be on continue watching?