I just applied for a non-0 last Friday in Vientiane, i had used my thai account for statement which i have since 2015 and i did not live in Thailand since 2019, they did not care why i have the Thai bank account yet, they just want to see if you have a minimum of 20,000 thb, your visa will be processed in 2 working days. Good luck!
If it's a visa on arrival, she first got 15 days and you can extend it for 7 days more, is she had tourist visa, she got 2 months in airport and then can extend another one month directly from inside Thailand.