Yeah but still, why would Quinn go to Bella's for Sage when they're already gone to the hospital, or stay there on her own if they were still there but went to the hospital?
That would imo only be the case if there is something connecting Quinn to Bella in that room, and I think most of us are pretty to almost completely sure (there is always a 0.1% chance in soap operas for twists like this) that isn't the case.
First of all, Quinn showing up there doesnt need to have a connection with the room at all.
During the game the group of friends we now have was just building up... Sage hated Jill (for no reason) before episode 9. Now they are besties. Jill and maya got closer too (Jill is already somewhat friends with Josy). Bella and MC are kinda the connection between them all. Quinn knows surely about that "bond" between those seven... (namely Derek, MC, Bella, Sage, Jill and J&M) And its shown that she is over her head with everything. Its not entirely certain, but it looks like she was burning down bridges, calling cops on vinny and buddy... and so on, Burke breathing up her neck too. Its safe to say, she needs people and help. Its not really shown in the game, but Sage mentioned earlier in the game that she sees Quinn as a trusworthy friend, and maybe thats true and Quinn does see her as a friend too not just a tool. Its clear as day that quinn doesnt see all people just as tools. What happend to Rio crossed a line for her too. Very much so.
Overall its not that far fetched to say... she is desperate at this point and needs some reliable people she can call out for help. The group around Sage and MC could be just that for her. I mean... who could she possible ask for help other than Sage and her friends? Nobody. She is out of options.
So all that in consideration... its not that unlikely that Quinn might show up at Bellas. Sage could have mentioned before that she will got for christmas dinner to Bella and so Quinn knows about that... And out of desperation heading over there to seek for help. And this move could be canon no matter the path.
But to be honest, iam totally tired of the guessing game about Bellas locked room and James... cause every theory was already discussed and not a single one makes 100% sense. There are too many flaws in every regard and i cant see a way how DPC will solve this thing so it will be 100% plausible.
Other than that, i believe its patrick that shows up there. But whatever, i am done with discussing theories about that part... its just tiresome at some point cause there is just nothing new to it, because we are discussing those theories since episode 9.