How to level up your guests once your Manor reaches level 2 and up.
Leveling up the guests (Normal mode only)
Assign Julia to the lobby then click on the numbered circle in the upper left corner of the lobby. Click on the desired guest level (1-5) then click the Play button.
Please note, the guest levels cannot exceed the current Manor level. Also, leveling up the guests do not count towards any guests currently staying at the Manor.