After much deliberation, and with the help of my friends, I've decided upon a surname for Amber and Jade. Henceforth they shall bear the last name of Warde, derived from the occupation of "civil guard" or "keeper of the watch"!
Jade: "Thank you very much."
Anna: "...I was expecting you to pick Manning as their surname."
Why? Because it would be more fitting given their status as servants?
Anna: "Because you're indolent and difficult to motivate and would have gone for the least troublesome path despite your lofty objectives."
My characters are so mean to me, but I know I deserve it T-T
Anyway: Three cheers for Amber and Jade Warde! Hip hip hurrah! Hip hip hurrah! Hip hip hurrah!
Anna: "I can't argue with that. Hurrah!"
Nina: "On behalf of my family, I formally welcome to the Thomas Estate, Amber and Jade Warde."
Thanks again, Sly-san, Paddy-san!