Do I address an engagement card to someone I've never met?

[trainersandcake]

MN is always so good at this kind of thing! The work colleague I sit next to has just got engaged. We get on well, have lunch together frequently etc., and have socialised outside of work a few times, so I got her a card yesterday.

So who do I address it to? To, say, 'Jane and John' inside even though I've never met John? Or do I say 'Dear Jane, congratulations on your engagement, I hope you and John have a wonderful life together' type thing?

Both , presumably she talks about him

She does talk about him but it seems a bit overfamiliar when I've never met the guy.

The girl I sit beside just got engaged. Never met her fiance but it never crossed my mind not to address the card to Jane & John

Obviously use both their names?!

Both. Our new baby card from DH's work had messages written in it from each member of his team and most put my name in their message too even though I have only met one of them. It's their engagement, not just hers so it's nice to acknowledge the unity