My (Thai born) daughter in law is here ( NZ passport expires 7 months) visa exempt which she now realises expired on 29 March. She now has a new Thai passport as well. Can she go to Immigration, pay the overstay fine and have her new Thai passport stamped as currently in Thailand. Her NZ passport will only allow 1 extension before it becomes invalid for any new stamps anyway. With the Virus crap there's no telling how long she will need to stay here.
TLDR : Answer Summary
The individual is inquiring about the ability of their daughter-in-law, who is a Thai citizen but entered Thailand on an expired New Zealand passport, to resolve her visa situation. She is currently facing an overstay since her visa exemption expired on March 29. The community suggests that she can obtain a 1-year extension in her NZ passport based on her Thai citizenship, provided she pays a fee and presents necessary documentation. It is also noted that switching passports within Thailand is not allowed.