Do step-children have a right to a step-parent's life insurance policies?

No. Step-children have no rights or interest regarding a step-parent's life insurance unless they are a named beneficiary on the policy.

Step-children have no rights in a step-parents estate unless they are named in the step-parent's Will. In that case a step-parent can leave the proceeds of a life insurance policy to a step-child by their Last Will and Testament.