Ashley Kosciekowski, 34, of Knypersley Road, Stoke-on-Trent, had been charged with causing the death of Charlotte Hope earlier this year.
Kosciekowski also faced a second charge of causing serious injury by dangerous driving to Charlotte's mother, Helen Hope, who was also hurt in the crash that took place on April 9 on the A53 at Astley near Shrewsbury.
Appearing before Shrewsbury Crown Court, sitting at Telford Magistrates Court on Tuesday morning, Kosciekoswki pleaded guilty to both charges.
The case has now been adjourned pending the preparation of a pre-sentence report.
Judge Glenn said that no date could yet be set for the sentencing hearing, which would be scheduled when the pre-sentence report was arranged.
Kosciekowski was told he would be immediately disqualified from driving, and Judge Glenn added: "I expect you to co-operate with the probation service, it is very much in your interests to do so and I trust you will co-operate."
Miss Hope, of Shawbury, was in a Volkswagen Polo with her mother Helen when they were involved in a collision with a white BMW M140i driven by Kosciekowski.