From Fallen London Wiki (Staging)

Note: the Empress had two children whose names begin with L: Leopold and Louise. Leopold is <a class="external text" href="https://www.failbettergames.com/news/the-mysteries-revealed-again">confirmed dead</a>. Louise is on the Surface, so this probably isn't hers.

Also, I personally can't understand what the inscription in Correspondence is supposed to mean. Any guesses?