I second Miss Scarlet. I believe that she will think of you when she is in the dress.
I agree that she does not need the drama on one of the most special days in her life. Maybe there will be other chances to heal. You do not have to forgive to find peace. You can accept this is a person you do not want to be around but will ignore and not say anything for the sake of the peace of others (and really yours). There is no need to traumatize yourself by talking to them or digging up old bones. It is up to the wrong people to apologize. And if these ones ever do, you can say thank you for the apology.
Hugs Gutmutter. I sew too. I know it is a very special thing you have given her to make her happy.