Petty thank you letter question

[toostressedtobeblessed]

Writing a thank you to a friend and her parents.

How should address it? Mr and Mrs x seems too formal as I'm friendly and with them but it seems too matey to call them by their first names. Also don't want to go down the whole "to the x family" route... What would you write?

Dear all, ?

Do their names on the mailing envelopes and then cheat on the card by not addressing them at all. Just get to write the note.

Thank you guys so much for blah blah blah
Love,
Me

Does she know them very well? don't know how old she is, but is she was introduced to them by their first names then it's ok to use their first names.

I agree that 'Dear All' would be a handy alternative, but it might sound a bit odd if she is very young, in which case, if in doubt go with Mr & Mrs.

My DC have never been introduced to friends parents, they just get to know them gradually at the school gate etc. But I'd go with whatever you call them when you talk about them, it's first names all the way in my circle, no one uses title surname.