I see it as something that develops. Nicola is IMO on the verge of discovering romance. I think she saw Ginty and Peter, and wonders if maybe there isn't something in it, as long as it's her and not Ginty.

She's got no religious convictions, so could easily fit in with Patrick and probably after 5-10 years of marriage becoming a Catholic [I've instructed the convert class at our church for many years, and it is a common scenario].