What are the future estates (ex: Life estate, contingent remainder, Vested/not vested) created in this situation(O, A, Child, grandkids). Would the rule of perpetuities count if the kids and grand kids are alive like in this scenario?

"O to A for life, then to the oldest child of A who survives A for his or her life, then to A's grandchildren." At the time of the conveyance, A is married, has 2 children, and 1 grandchild