Thanks to SpiritWind (post 502) I found my bride swan on page 28 of my inventory, and my groom swan on page 29. (That's after force-closing and clearing both cache and data, don't know if those steps were actually needed.)
Also thanks to my neighbors for sending RSVPs; to get to 50 I had to ask some neighbors multiple times. I spent more days waiting for 50 replies than I spent performing the previous 9 steps of the event.
And thanks to everybody providing info on the forums, particularly those that gem ahead, so that I knew to start raising pigs early, bring my cottages out of storage, stock up on prime cuts and truffles, etc. Those hints help a lot.