By far the one strategy that is most likely to result in your wishes being carried out is this: work with an experienced estate planning or elder law attorney. That attorney can advise how to provide for your friend and "the kids," prepare the documents that will best meet your needs, and preside over a properly witnessed signing ceremony.
Best wishes for an outcome you can accept and please remember to designate a best answer.
This answer is offered as a public service for general information only and may not be relied upon as legal advice.
Under Mississippi law, if you have a will properly executed (put into effect) you can do just what you describe. There are technicalities that need to be in your will to make sure your wishes are carried out just as you specify. Consult with an attorney of your choosing to make sure it is worded well and executed properly. That is the only way to know your assets will pass to who you choose.
This creates NO attorney-client relationship and all answers are for general information. All persons are encouraged to consult with a licensed attorney of their choosing for advice specific to their need(s).
If you have a properly executed will you can leave your assets to any one you wish (with certain exceptions in LA. Unless other persons can show you are not mentally capable of executing a will or someone exercised undue influence over you in writing the will, you can leave your assets to anyone you choose. The exception to this is if you have a spouse, in which case that spouse has certain rights automatically in your assets by state law.