For instance, the reason why you have to put the stepmother in red-hot shoes and make her dance until she dies is that if you don't, she comes back when you have your first baby, murders you, and puts her stepdaughter in your place. (You get better, but still it's more fun to skip that episode.)
But that's only one of the variants.
Was working on another, where the heroine is kidnapped after the wedding. I, for reasons of plot profluence, put it right after the wedding. Then I thought. . . hmmm. . . .
Now, stepmother villain or none (none in this case), the traditional time is just after the first baby. Other times include going on a journey or violating a prohibition. But at the wedding itself is atypical. The only person who can interrupt wedding festivities is the hero, or heroine, having arrived just in time to stop the love interest's union with the false hero(ine).
The downside of that is that I have to put in some time then.
OTOH, I was contemplating some Chekhov's guns to plant.