OK, scrap the cute kiddy scribbles then!

I think if it was me I'd probably find some greeting cards I liked, not necessarily wedding-related, just a design I liked... and write something inside along the lines of:
TammySue & Brendan are happy to announce their marriage on (date), we celebrated the occasion with names-of-children - here is a photo of us all on the special day (etc...)
You know what I mean..! I don't think that has any underlying tones of "give us presents now!" does it? You can make it sound better than that, obviously...
Jo