Does the beneficiary of a life insurance policy have to share the funds if the will says to split equally between 3 children?

If the beneficiary was to do that, is it a gift or is it considered part of the inheritance?

If it is a gift, is there gift tax to be paid by the giftor or giftee?

I know that the "estate" is responsible for the estate tax as a whole, but, if the estate is primarily pod and beneficiaries, the tax $ has to come from the beneficiaries. In determing how much to get from each beneficiary, wouldn't it be based on the tax % applied to the value of what each individual received, or is it to be split equally between the 3 children (one child has gotten more than the others, so we feel they owe more on their share of taxes)? Thank you!

There could be lawyers who would accept fees to try and make a case of denying benefits to a child whose name does not appear as a beneficiary in the Life Insurance Policy. However it would be best to divide the proceeds in the manner desired by the deceased policy holder.
Payment from an individual account that receives the Life Insurance proceeds to any other party to whom the deceased has willed a share, could attract gift tax if the will of the deceased has not specified such a share. However the estate of the deceased cannot be taxed for Life Insurance proceeds.