Known in Thailand by her nickname Ung Ing, Ms Paetongtarn has become a very familiar figure here since leading her party, Pheu Thai, in the general election last year. She proved a popular campaigner, speaking at rallies up to the last month of pregnancy with her second child.
However her family, in particular her mother Potjaman, who is still a powerful figure in Pheu Thai, did not want her to become prime minister, fearing she would be vulnerable to the kinds of legal interventions which forced both Ms Yingluck and Mr Thaksin into exile.