Rules Of Etiquette

I was wondering if any of you knew the true, Martha Stewart-like rules of etiquette (not just opinions), when addressing the following:

1.) If inviting a widow and her new boyfriend, is it -
"Mrs. John Jones and Guest" or "Ms. John Jones and
Guest"?

2.) What do you write when inviting a single custodial
Father, his children, and the new girlfriend? I was
Thinking - "The Jones Family and Guest", but then
Started to worry that he may think that "and Guest"
Was for the older child.

3.) What do you write when inviting a husband and
Wife, but the wife emphatically uses a hyphenated last
Name? (For example: John Jones and Jane
Anderson-Jones) Should you still write - "Mr. And
Mrs. John Jones"? or "Mr. John Jones and Mrs. Jane
Anderson-Jones"?

Any knowledge that you may have would be greatly
Appreciated!

Thank you in advance,

Audra