Can I extend my visa at Chang Wattana if my TM30 is registered in Chonburi?

well, from what you've posted so far, you got another week on your current stamp

BUT

why are you burning down the time on this stamp without checking on what exactly they want at the immigration office as far as getting your extension?

Go to the immigration office and find out exactly what's required. You don't lose any time getting the extension early, they ADD it to your current expiration date.

@Lee ************

you apply for the extension at the immigration office that serves the area where you live. It has nothing to do with where the mother and child are listed in the thai house book listing it has to do with where you all live.

I'd say take the mother, child, the relevant bank statements, documentation photos copies of your lease and your passport to the immigration office at Chaengwattana and see if you can get an extension.

You will probably be required to file a TM.30 (which you can do by yourself without any documentation from your land lord other than your lease) and you'll probably get an 800baht fine because you needed to file a TM.30 within 24 hours of moving BUT then you should be able to get the extension.

If you are applying for a yearly extension of stay you're definitely going to have to file a new TM30 using a bangkok address or you're not gonna be able to do it at Chaengwattana.

that would be a NO. :O

You'd need to file a NEW TM.30 with the address in Bangkok where you're staying.