Rhonda Mitchell, of Kalkaska, pleaded no contest to a charge of moving violation causing death in the April crash involving members of the Grayling golf team.
Mitchell's plea was part of a plea bargain. She was originally facing charges of manslaughter and moving violation causing death.
The no contest plea preserves the family of the victims rights if they press civil charges.
Kalkaska County Prosecutor Mike Perrault said he hopes this case will help prevent people from driving recklessly.
A police investigation released in June shows both Mitchell and Grayling High School golf coach Jason Potter were at fault in the crash. Potter, who was driving the van carrying members of the Grayling High School golf team, was killed in the crash.
Potter's toxicology report showed no signs of alcohol or controlled substances. Mitchell's, however, showed she had marijuana and morphine in her system.
State Police say Mitchell did have a medical marijuana card, but it had expired a year earlier. She also had a prescription for the morphine.
Player Louis Menard also was killed in the golf team's van and five other players were hurt.
Cassandra Stapleton, 27, a passenger in the van Mitchell was driving, was also killed.
Mitchell was the legal guardian of a three year old also in her van. She was not hurt.
Mitchell will be in court on Oct. 2 to be sentenced.