As you illustrate the problem, you may come up with the same diagram as the one shown in the attached picture. The relative velocity is the linear velocity between the two velocities. This is calculated by simply finding the difference of their velocities. Since, the velocity is with respect to Jane relative to Mary, the solution is as follows:
Relative velocity = Velocity of Jane - Velocity of Mary
Relative Velocity = 4.67 m/s - 3.59 m/s = 1.08 m/s