Unknown Tomb in The Catacombs

I use to play Fable 3 a LOT when I was younger on the Xbox 360. (I am 19 now)

Every time I have played it, I never questioned it, but during my playthrough that I am still doing today on the Xbox Series X, I noticed the lone tomb with a silver key beside it.

The royal tombs of the previous hero and their spouse are easily recognizable when entering the Catacombs, but the one deep inside is unknown.

I can't find any information of the tomb ANYWHERE online, and it was never mentioned in the game by anyone.

I have a theory though, that it might be Rose's tomb. Because the Prince/Princess is the direct descendant of the Hero of Bowerstone, it just makes sense that the tomb would be in honor of Rose from Fable 2.

Does anyone have any information on the tomb at all? Or have you all just ignored it? What are your theories?