First what e reason for giving? Example by tradition CNY: You do not need to give red packet to someone who is same “rank” aka 同辈 as you but older.. Irregardless if e person married or no.. If wedding: if you’re already married you can give under “you and your wife as a family” If you have not, then just chip in e money to your parents’ angpao and make it as a angpao from your family..
My dad said not needed. For 长辈 only need to give great/grandparents and parents. Those 三姑六婆姨妈姑姐 also not needed. For 晚辈, younger siblings and younger cousin (child and 辈分lower than you). For myself, my husband have a lot of similar aged cousins who are single (all younger 辈分) so we give. For older cousins (also younger 辈分), we don’t give regardless married or not.
my understanding is married give to unmarried of course nowadays is more to personal preference like me, I don't give ang pow at all but recent year have to cause I feel pai seh as my 2 children receiving angpow
in my family, we do. follow the cousin's age for angbao rules.