If a parent is in aveilos, can they dance at their own child’s wedding?
Mazal Tov. You should have much nachas from the new couple. Regarding your question, during the year of aveilos, a parent may attend, dress in shabbos clothes and partake in the dancing of their child’s wedding.
Rema 391-3, Nachlas Shiva 2-17, Divrei Sofrim 391- ftnt 62.