I am divorced. Can I make my oldest of 3 kids the beneficiary my life ins., then declare details in my will ?

What I am asking is this. I am concerned about my health. If something were to happen to me, say within a year, instead of my 3 kids each being a beneficiary of 1/3 each of my life insurance, can I declare my most mature child the sole beneficiary ? Then, declare in my last will how I would like her to divide it with my other 2 kids? The reason I ask this is that my oldest is 22 years old and my most responsible, close to graduating college and very close to starting her own career. My other two are 20 and 16. I would be concerned about putting a large sum of money in their possession due to their level of maturity. I think that my son ( 20 ) would use it very unwisely at this point in his life and my youngest daughter seems too young to manage it very wisely as well. After reading, some of this, it would be nontaxable if my oldest was the beneficiary of my life insurance, as opposed to letting the life insurance money become part of my estate, which would be subject to creditors and taxes . I was hoping I could declare her the beneficiary, then explain in my will how she should divide it up with a few provisions. She will also be my executor in my will. I hope this is understandable. Thanks for any help you can provide .....