Depends how old they’re meant to be. People say mid 20s but I get way more 14 year old girls vibe. Good chance since it’s a kids show all of them are innocent of that and none of them have had sex. I bet that they have jobs and homes but I don’t think pony society is 1:1 with ours in that regard. The real question is if celestia has had sex- is she a more christian type angelic being or is she more like a greek goddess? It seems the matter, so there’s no reason she can’t have reproduced with other deities or mortals and birthed concepts like the sea or the sky like in hesiod or like weird magic creatures and other gods. I like to think she’s had cosmic deity flings and romances in the mythic history of equestria. Also, I had sex with all the ponies, all of them, so they’ve actually all had sex