I’d look a little more. Picture the twins as 35 and trying to move ahead professionally. People won’t know what gender Sidney is, which is just irritating when setting up appointments or meetings and you don’t know have a clue who you’re looking for. He will be teased constantly in school. Adelaide has more of an elderly English aunt tone - not a strong name for a woman professional. Don’t saddle the kids with names that have some romantic connection for you, if those names will make their lives more difficult.