There is a difference between the valid until or use before date on the visa itself, which indicates you have to use this visa to enter Thailand to get a period of stay.
Using the visa on entry gives you maximum 90 days of stay, which can be extended twice at immigration with another maximum 90 days and three times 90 makes it maximum 270 days of stay inside Thailand.
After your wife gets 50 years of age, you both can apply for the Non Immigrant O-A visa but both of you need to meet the requirements.
There are less requirements for your wife to apply for the Non Immigrant O visa based on being your dependent and get 90 days of stay on arrival which can be extended with another 9 months at a Thai Immigration Office after 45 days of arrival, this to match your stay you got on entry.
If you want it to do in Thailand you need to transfer money into a Thai Bank before you can apply, opening a Thai bank could take some time but also need time left on your current stay.
Your applicaltion is under consideration and you must report at the same immigration office on 9 May 2022.
The first picture is a notification of stay due the fact that on 11 Jul you are 90 days inside the country.
Small advice, you are allowed to ask questions to the Immigration Officer if you are still confused or not understanding the stamps, rules or regulations.
Your friend can pay the overstay there, BUT the Immigration Officer can reject a new application for an Extension of Stay, in that case she will have 7 days to leave the country.
Other option is to buy a ticket out of Thailand and pay the fine on the airport, but make sure your friend does not get cought out by an check point.