In fact, given the current status and reputation of the Prime Minister's Mansion, inviting someone to arrange a marriage for the legitimate eldest grandson is simply too easy, second only to the Emperor and the Empress Dowager.
But if Song Zhiyuan wanted the Emperor to arrange the marriage, he wouldn't have asked Song Ci and the others to negotiate it, so it's clear he wasn't considering that option.
The original Song Ci's social interactions were also simple, with only a handful of close acquaintances. The current Song Ci maintains the original old lady's low profile and hasn't expanded her social circle. Her close contacts remain just a few people, with the Empress Dowager Wang first, followed by the old Wei family, Princess Anping, and others.
The intended marriage match for Song Lingsu is the noble lady of the Duke Mansion, so Song Ci thought of approaching Anping. A princess matchmaking is both dignified and full of sincerity.
