Who should i make my waifu?

Hey,
I have a +spd/-hp +3 Soleil and a +spd/def Lucina. But who should i make my waifu? They will paired with a support brave Lucina that gives every stat +5 if adjacent (her weapon + drive def and drive res).
Also should i change my Lucina’s bond skill (weapon) to seal Falchion? And should i change her build?