The Starlight Sentinel is still purchasable in-game--albeit on the Market Board. They run for about 300k on my server.
I'm assuming people can maybe (?) buy them from the Calamity Salvager, and then maybe sell them on the MB like they do the Dream outfit? I'm not sure since I didn't get the Starlight Sentinel last year, so I can't check.

The Star-topped Sentinels are also available on the MB, but they're 5+ mil on my server.

If the items can be purchased from the Calamity Salvager, and subsequently traded, I know it's not the same as earning it through an event, but maybe you can gift one to you wife? That way she can have one, too?