To add to the list; the lala twins also mention their wish to take F'lhaminn as a bride, to which F'lhaminn replies she can only sing for one (assuming Nielle)
I'm under the impression that marriage is treated much like it was in the middle ages/medieval times (arranged marriages for political gain or monetary gain), and probably originated from the Hyurs and/or Elezen.
The city dwelling miqo'te, or the miqo'te that have left their tribes for years are probably a lot more receptive to the idea of marriage than the ones that remain in their tribes.
