The woman who will lead the southern state of Tamil Nadu will face challenges including winning public support amid corruption allegations, analysts say.
On Sunday, Ms V.K. Sasikala, 61, a former video rental shop owner who has never contested elections, was unveiled as Tamil Nadu's next chief minister, two months after the death of her predecessor and close friend J. Jayalalithaa, a charismatic actress-turned-politician.
This was after interim chief minister O. Panneerselvam stepped down, citing personal reasons.
In the last few weeks, Ms Sasikala has started to look like Ms Jayalalithaa, from the way she wore her hair in a bun to donning green saris.
The politician, whose death sparked an immense outpouring of grief, was called "amma" (mother), while Ms Sasikala is known as "chinnamma" or mother's younger sister.
Yet a graft case in which the two friends were implicated threatens to stop Ms Sasikala's rise to the top.
India's Supreme Court yesterday said it would be delivering its verdict on the appeal likely next week on the 1996 graft case involving 660.5 million rupees (S$13.9 million) in which both women were accused. A conviction would bar Ms Sasikala from holding a government post.
"Her biggest challenge is the image she has with the people of Tamil Nadu. There are corruption cases... Unlike Jayalalithaa, she is not a popular leader and has no grassroots support," said Chennai- based political commentator Badri Shesadri. "She is seen as a usurper," he added.
Tamil Nadu is seen as one of India's more prosperous and better administered states.
A car manufacturing hub with a strong bureaucracy, the state has been going through uncertain times since the death of Ms Jayalalithaa, who was popular for welfare schemes such as those offering subsidised food to the poor.
Critics noted that Ms Sasikala's administrative abilities remain untested and she has never contested elections, or had held any political position until she took over as party chief of the ruling All India Anna Dravida Munnetra Kazhagam after Ms Jayalalithaa died from an illness at age 68 last December.
While the ruling party now enjoys a comfortable majority, once Ms Sasikala is sworn in as chief minister, she will have to contest and win elections within six months.
The date for her swearing-in is yet to be announced but the resignation of Mr Panneerselvam was accepted by the Tamil Nadu governor yesterday.
"There cannot be a greater setback to politics in Tamil Nadu, There has to be some respect for the people's mandate. There is a strong disapproval rating for her," said political analyst Ramu Manivannan of Madras University.
Ms Sasikala met Ms Jayalalithaa in the late 1970s, with the two women striking up a deep but tumultuous friendship that lasted for decades.
Over the years, Ms Sasikala had unparalleled access to Ms Jayalalithaa. But they also briefly fell out over whispers of her family growing powerful from the friendship.
In 2011, Ms Sasikala and her husband M. Natarajan were expelled from the party. She was later brought back into the fold but not her husband.
In 2014, the two women were jailed briefly in the corruption case but later acquitted.
Ms Sasikala was the one managing party affairs during Ms Jayalalithaa's illness.
Party functionaries maintained that Ms Sasikala had brought stability to the party amid reports that cadres were not happy about the development.
Meanwhile, Ms Jayalalithaa's niece Deepa Jayakumar has expressed her intention of staking claim to her aunt's political legacy by contesting elections and following in her footsteps. She currently has no position in the party.
"The party is intact now, that is the biggest thing. There is more clarity," said a functionary of the ruling party.