Can it tell voices apart?

Speaker diarization is the term you are looking for, and this is more difficult than simple transcription. I'm rather confident that someone probably has a good solution by now (if you want to pay for an API), but I haven't seen an open-source/open-weights tool for diarization/transcription. I looked a few months ago, but things move fast...

Diarization is on the roadmap; some providers support it but some don't and the adapter for that could be tricky. Whispering is not meant for meeting notes for now; for something like that or diarization I would recommend trying Hyprnote: https://hyprnote.com or interfacing with the Elevenlabs Scribe API https://elevenlabs.io/app/speech-to-text

I'm not looking for attributed meeting notes, so much as making it harder for a passing child to inject content.

Thanks, that, yeah. I've looked occasionally but it's been a bit. Necessary feature in a house with a 9yo. I've been thinking about taking a swing at solving my problem without solving the general problem.