In which case can Sheila's accident involve an insured motor vehicle?

The situation where Sheila's accident can involve an insured motor vehicle is when the driver had insurance but became insolvent. In this scenario, the insurance policy is pertinent because it indicates that there was coverage in place at the time of the accident, even though the driver can no longer fulfill their financial obligations due to insolvency. This suggests that Sheila may have grounds for a claim through the other driver’s insurer if she can prove liability, provided that other legal conventions or protections apply, such as under a provision for uninsured or underinsured motorist coverage.

In contrast, the other options concern situations where there is either no coverage or the vehicle involved does not qualify as 'insured.' For instance, in the case of a collision with a tree in a rented car, although the vehicle is rented, the situation does not pertain to another motor vehicle's insurance. A hit-and-run incident typically leaves the victim without a means of claiming against the at-fault driver's insurance, leading to the conclusion that it cannot involve an insured vehicle. Lastly, when a driver without insurance hits her car, this likewise references a scenario lacking any insured motor vehicle involvement. Thus, the option involving an insured but insolvent driver best fits the context of involving an insured motor vehicle.