I do not and I don't believe she did either. It wasn't a full castle, just some ruins, and a small room. You can see it on her stream here: https://www.twitch.tv/geminitay/v/2552002364?sr=a&t=8692s
I've found the exact same spot but there's no ruin there. Some smaller ones nearby, but they vary each time I recreate the world.
Edit: she shares the seed and you can see her worldgen setup (it's also pasted on her discord), if you want to try yourself.
The only major variable is that I'm on Linux and she's on Windows. Could that be affecting the random number generator perhaps? If so, why is the terrain identical?