That seems to make sense. However, we have been told that the transport provision is part of the young woman's employment. Even part-time employment brings obligations to comply with a mass of rules that wouldn't necessarily apply if the arrangement was less formal.
If, in the course of her employment, she is carrying a child, there may also be an obligation for her to undertake a DBS check. She should check with her employer.
I agree. There seems to be an element of hire and reward in this arrangement, especially since it arises from what has been described as a job. She might also wish to check that there is no requirement for the vehicle and her to be licensed by the council as a private hire vehicle and driver...