The Central Bureau of Investigation (CBI) did not file a second remand application for her in the court.
Shashi is accused of taking the alleged victim to the spot of the crime and for the same, she has been included in the case as an accused.
Sengar's brother Atul Singh on Tuesday was also sent to four-day police custody by a CBI court.
Along with Atul, five other accused in the case were sent to police custody too.
On April 13, the CBI arrested Sengar on the charges of raping a teenage girl. He was later sent to seven-day CBI custody.
Earlier, Uttar Pradesh Police had charged him under sections 363 (kidnapping), 366 (abduction of woman), 376 (rape), 506 (criminal intimidation) of the Indian Penal Code (IPC) and Protection of Children from Sexual Offences (POCSO) Act, and handed over the case to the CBI.
The teen had accused the MLA of raping her in June last year.
The victim's family had also alleged that the accused MLA's brother, Atul Singh Sengar, along with his companions, had also raped the girl and thrashed the victim's father on April 3 for refusing to withdraw the FIR over the same.
The victim's father died on April 9 due to multiple injuries. (ANI)