As a writer who occasionally gets published in journals and anthologies, I get asked for an "author's bio," usually with a limit of 50 or 100 words. I have a few things that I include but always feel like I could write a better bio. Writing credits, social media links, personal info (like "married and lives in...") The only one I'm really sure about is the writing credits. Are there any standards, guidelines or suggestions as to what should and should not be in a short author bio?
I don't think there are standards. I would NOT include any personal information that doesn't add to your credibility in the main topics you write about.
In the modern world, I would not even include the town I live in; perhaps the State or region.
But if someone writes about homosexuals and is one, it lends credibility; if someone writes sci-fi and is an actual scientist of some sort, that adds credibility; if someone is a lawyer that writes law-based fiction, that adds credibility; and so on.
In general, look at your bio as a sales pitch to convince readers you can write whatever they are looking to buy. It's a job interview! If it is literary work and you have degrees in English or Literature, let fly. But if you have degrees (like me) in Mathematics, that is not a clincher for writing literary works, for readers it is likely a counter-indication of quality, so leave it out. If you graduated from XYZ university, say that and leave it at that, degrees are usually taken as an indicator of quality and clear thinking, so they are good for a sales pitch.