What should my friend do about her Non-O visa after getting divorced in Thailand?

Okay sticking straight to the VISA related question in your post.

She would need to go cancel her extension of stay when she got divorced because the reason for her extension changed. There is NO grace period.

Normally people who are getting divorced know this is happening and plan ahead (move the required funds into a thai bank account in their name only so it can be seasoned the correct amount or time.

She wouldn't be able to get a year extension based on retirement using banked money unless the money was in her account for 2 months BEFORE she applies for the extension.

So she needs to either move the money into her account and then drag her feet for two months before she agrees to the divorce, OR she needs to agree to the divorce, cancel her extension, go on the blanket amnesty until July 31st, move her money here and then see what happens once the borders open up as far as her and a long term stay.

And time to close it down. As I understand if all in good standards, it could be arranged quickly. But as we do not know the circumstances, assets, etc we can only advice on the visa part and that advice is given. Good luck.

Talk to a lawyer not a fb site.

If she does not want to get a divorce yet, just don't go to any Amphur / local Registrar. Doing it through the court takes a lot longer and can be expensive. When the time is right, just make an appointment with District Chief (Nai Amphur นายอำเภอ) and meet up with ex and get it done at an Amphur.

The bottom line is don't sign anything until you figure out a visa. There's no rush.

I guess it takes a little longer than we go tomorrow and we are divorced, court does not work that quickly,

If she is on an Extension of Stay this must be cancelled on the day of the court order as divorced. If she likes to apply for a new Extension of Stay she need to have 800.000 Thb on her Thai bank account at least 2 months prior application date.