She died 40, and is survived by her son, state JD(U) spokesman, Ajay Alok, besides her husband.
Chief Minister Nitish Kumar was among the earliest to visit Sinha's residence to offer condolence to the bereaved family.
In his message, Kumar described her as "a great educationist and social worker".
Senior BJP leader C P Thakur, Minister Shyam Rajak, JD (U) MP RCP Singh, Ranjan Yadav and a large number of legislators and people from different walks of life paid floral tributes to the deceased.
Actor-turned-politician Shatrughan Sinha, Bhojpuri actor Kunal Singh and former minister Parveen Amanullah are other prominent candidates from this Bihar's capital seat, the fate of which will be decided tomorrow.