Monta "Ying Kai" Yokrattanakan, whose trial on multiple charges including human trafficking is just beginning, was sentenced to seven years and six months in jail for lese majeste on Tuesday.
Appearing in Bangkok's Ratchadapisek Criminal Court where witnesses in the lese majeste case were to be examined, Monta changed her plea to guilty on charges of claiming on three occasions in 2012 to be a royally appointed khunying.
Prosecutors offered no objection and she was promptly handed a 15-year prison sentence for lese majeste, commuted to seven and a half years because she confessed.
Section 112 of the Criminal Code requires that anyone who defames, insults or threatens the King, Queen, Heir-apparent or Regent must be imprisoned for three to 15 years.
Monta, who has been held at the Central Women's Correctional Institution since her arrest last year, is also accused of trafficking in people, filing false complaints to police, and harassment.
The trafficking charges involve two cases, in one of which she allegedly coerced young women to work for her as housemaids without pay or days off in 2006 to 2010. In the other, a third woman was allegedly employed under the same conditions from 2008-2010.
Monta is also accused of filing false theft complaints against her 19-year-old former maid, Prapawan "Goi" Jaikla, for which Prapawan spent three months in jail. The teenager was reportedly "punished" for refusing Monta's offer to work abroad.