Most display devices cant mirror to other devices (e.g. Samsungs can do this), rather just be mirrored to.
There are probably some more expensive/involved solutions to this but since your friend mentioned specific simultaneous Disney Plus requirements...
.... I heard from a friend that, yes, it's possible, but not the way your friend is thinking.
Your friend needs to:
- get a Roku, hook it up to the "Dumb" TV,
- make sure the Disney+ app is added to both devices,
- make sure both his daughters have Disney Plus profiles, then
- In the Disney Plus app on one of the devices (or another device), select the movie/show, then choose Groupwatch.
- then, from a browser/mobile app, start a Groupwatch for the specific title, making sure to add both profiles to the Groupwatch (might have to copy/paste the link into another browser tab/session and then login with that profile).
- Start the Groupwatch (from whatever the host device is), and control playback from there (pause from anywhere).
This method requires a decent internet connection since the same movie will be streamed (at least) twice "simultaneously".
Be prepared to be patient with the initial setup and "syncing", but once its all synced, it works well.
(Also, your friend can have up to 6 "Groupwatch members", from any location).
