Suzanne Lammers was sentenced Thursday in Montgomery County Court. She was ordered to begin serving her sentence immediately.
Lammers' attorneys had requested house arrest, but the judge sent her to jail instead, citing her failure to come forward after the crash.
Lammers struck the 13-year-old boy as he rode his bike in Bryn Mawr in July 2009. The teen suffered a broken leg and other injuries.
Prosecutors had pushed for jail time, saying Lammers tried to avoid being caught.
Police found the car parked in Lammers' Villanova garage with a blanket covering the damage.