This was addressed just two pages ago, maybe do some leg-work yourself and then you don't have to wait for some random to decide to reply?
https://f95zone.to/threads/being-a-dik-v0-5-2-dr-pinkcake.25332/post-3880349
She isn't necessarily in that locked room.
Sage says she was avoiding her father, so she may have been on the move the whole time and unknowingly moved past the MC at some point while he ducked into a room.
You don't see several other HOTs as they're moving around the building either (Camilla, Lily, Mona etc.), DPC mostly only puts them on screen when he wants the MC to interact with them during this freeroam.