Can someone purchase life insurance on their great grandchild?

I have a possible client that wants to know if they can purchase a whole life insurance policy on their great grandchild in Indiana. Not sure, but I thought when I took the test it could only be the grandparent or parent. They want to make sure either generation in between doesn't have access to the policy to let them cash it in whenever they wanted. Because I like to be able to document anything I tell a client where could I go to find this out? Thanks for any info.
If you want this in a documented way, call the carrier and ask. They will say yes, but get the name of the person you spoke to, the date and time, and write the policy.

When you submit the policy, they may ask about the relationship. If doing a paper app, I would explain it on a cover letter.