If a Muslim woman cannot display her beauty to non-Mahram individuals, including at mixed gatherings like weddings, then should she avoid attending such events? And if she does go, how should she present herself?
Bismihi ta'āla
A believer must avoid free mix-gatherings, for whatever reason it may be, and as close as the non-mahrams may be. We must try to promote segregated wedding programs, and not allow ourselves to participate in haram gatherings.
This works for both genders as well. A man should not attend, and a woman should not attend as well.
It is by far better for weddings to be segregated, so that the women can dress as they wish, without hijab or any restrictions.
If someone is forced to be there, like the person being a primary family member, then they go just for the social obligation they have, limit it to that, dressed Islamically, and leave.
And Allah knows best