What a change in the political landscape in Thailand, with Yingluck Shinawatra now poised to become the country's first female prime minister after her opposition Puea Thai party won more than half the seats in parliament on Sunday.

Yingluck has already made it clear that social reconciliation is one of the main priorities on her agenda, and one of many challenges she must deal with is restoring political stability in her country.

Only a day after its victory, Puea Thai has made the wise move of forming a coalition with four smaller parties in order to get the solid support they need within the parliament.

But it is crucial for Yingluck to quickly move out from under the shadow of her elder brother, Thaksin, the country's most divisive personality, and one who many believe is the de facto leader of Puea Thai.

Thaksin is currently in exile in Dubai to avoid a two-year prison sentence on corruption charges.

Puea Thai's supporters, the so-called red shirts, are mainly the rural and urban poor, while the defeated Democrat Party is backed by the social and political elites.

The tension between the two parties reflects the deep divisions within Thai society, and these will only become wider if Thaksin returns under a Puea Thai push for political amnesty, an early campaign proposal.

Although Puea Thai later stated it did not support an amnesty, and Yingluck is now trying to distance herself from her brother, insisting that she is not his "clone" and can make decisions on her own.

The prime minister-in-waiting and her party still have to reach an understanding with the military, and a legal tussle may be another stumbling block to Puea Thai assuming power.

A leader of an anti red-shirt network has filed a petition with the Department of Special Investigation against Yingluck, asking that she be charged with perjury for giving a false statement regarding Thaksin's assets.

The Supreme Court last year seized billions of Thaksin's assets, which were alleged to be of questionable origin. The court dismissed testimonies by Yingluck and other defense witnesses as unconvincing.

Yingluck may need to clear her name by placing her financial connections with her elder brother under public scrutiny.

On the foreign front, the incoming Puea Thai government will have to tread carefully but sure-footedly to solve the protracted border dispute with Cambodia.

Yingluck, 44, a business woman with no political experience, will have to pass tough tests before proving herself an able leader of a country whose political fortunes have been in almost constant flux in the last few years.