So you've saved Mia, and had the next movie with her (together with her unwilling co-start)? If so, pass me your save game folder, I'll have a look, see if I can work out what's going wrong.
If you're on windows, the path should be:
C:\Users\USERNAME\AppData\LocalLow\Droid Games\Making Movies
Just zip up the whole thing and send it over to droidproductions@protonmail.com