If you purchase the policy you can name anybody as the beneficiary. If the policy will be for small amount of money that would be fine. If you are going to be getting a larger policy, I would go to a lawyer. The lawyer can set up a trust for your daughter with your brother named as the trustee. The life insurance would go to account to be used only for your daughters benefit with your brother deciding how to give it to her.
You would be better off naming your child as the beneficiary so the money goes into a trust until she reaches a certain age. Your will needs to state that your brother will be the administrator of the trust. That way, he is in charge of the money and can use some if it for your daughter, the balance would be held in trust to be given to her when she reaches a certain age. That would be the safest way to handles it.