Is it ok to multi client in a public server (one that’s been globalled) if one client is spec?

No, it is definitely not ok to multiclient anywhere.

Just mentioning this because I remember hosting a bet server a week or two ago and somebody was doing it. I think they got reported though ( was (Wet)Dream multi clienting with an account called (Wet)Brazilian)

Good, if they got reported they're most likely going to be in trouble.

It’s ok to play with family members, I’m trying to find out if it’s ok to have 2 windows with toribash running and have both windows in the same server, which makes it like one account is in the server and so is another but both are being played by you.

Every server that has been globaled is considered public therefor you are not allowed to multiclient in those rooms either

I'm not sure I get why its not allowed, in tourneys and ranked servers sure, but what harm are they doing in say public6?

If they deliberately draw over and over for example that wouldnt be allowed whether it was a multiclient or not. And the argument of "what if its the same person and they want extra goes" becomes a bit moot as well when you consider that its painfully obvious if theyre the same person because they cant type at the same time and it would be really easy to see if they ended up playing against themself