The former civil servant, known only as Anchan, posted audio clips from a podcast on social media.
The 63-year-old said she had simply shared the audio files and had not commented on the content.
Thailand's lèse-majesté law, which forbids any insult to the monarchy, is among the strictest in the world.
After a three-year break, Thailand revived the controversial law late last year in an attempt to curb months of anti-government protests, with demonstrators demanding changes to the monarchy.