Can I extend my Non-Immigrant O (spouse) visa for 30 days without leaving Thailand?

Nope it is not, you cannot get a 30 day extension on a Non-Immigrant type visa.

You MIGHT get a 60 day one time "visit thai family" extension

but

you'd have to go to the immigration office with your thai wife to check the exact requirements. <- as in I don't know if they'll let you do it without having the marriage registered here in thailand

I remember you're the one that didn't have the US marriage certificate legalized before you came here and are trying to get the marriage registered at an Amphur in country, get the Kor Ror 22 so you can apply for the year extension based on marriage to a thai. 🙂

If you can't get what you need before your 90 days runs out OR get that 60 day visit thai family extension, you're done. 😕

You would have to bounce out/back to get a new 60 day free entry stamp then start the process inside the country first for a new 90 day Non-O visa for 2000baht at the immigration office, then 2 months later a year extension for 1900baht