I spent all my career working in 'small' companies where we flew with the same Skipper / FO combinations very, very regularly.
During those years, my own experience was that there were good pairings and bad pairings, for a whole variety of reasons ( personality, history, culture and others ) and that a night working in a 'bad' pairing was a horrible night's work.
Same for a husband / wife pairing I suppose - some days or nights would be better than normal, some worse than normal, all depending on what's been going on during the two or three hours together before Report Time.
But I'll have to say - I'd find it difficult working with wife / son / daughter in a cockpit environment if my family are anything to go by and we class ourselves as normal....