Umineko ep 2 murders [spoilers]

[WinterfuryZX]

I was reading this vndb thread: https://vndb.org/t4019 (Beware: MASSIVE SPOILERS) along with my reread of Umineko and I was thinking if it's possible to not think

 

of Rosa Ushiromiya as an accomplice of Sayo Yasuda:

we have a red truth and a couple of events witnessed by Battler that pretty much cement suspiction on her:

- Rosa reporting betarice's sleight of hand as magic to the rest of the family (witnessed by Battler)

- The magic circle graffiti on the chapel's door (witnessed by Battler)

- "Starting when Maria's key was received, and until the instant Rosa unsealed it the next day, it passed through no one's hands!!" (1st Twilight, Red Truth)

- Battler finds a sealed letter inside the parlor. The doors and windows were all locked. (witnessed by Battler)

If we think of Maria Ushiromiya as an innocent accomplice of Sayo like in the 1st episode, it is possible that Maria itself locked the chapel creating the illusion of a locked room (after that either Sayo resealed the letter with Kinzo's sigil without properly "taking" it from Maria or Rosa, in the rush, didn't notice the seal was broken) and placed the sealed letter inside the parlor after Sayo's suicide. It's also possible the graffiti was drawn by Sayo...

I cannot explain the "magic" though, Rosa is not so stupid to mistake a cheap trick for magic, her behaviour is definitely suspicious there.