I am not licensed to practice law in Virginia; however, as a general matter, you would seek power of attorney to manage financial or medical decisions for someone who is alive but unable to do those things for themselves, such as an elder parent with dementia. There are many possible questions here, but I will try to answer the one that seem most probable to me. If you are trying to get control over your loved one's assets for the benefit of your children, there should be process in your state that will allow you to do that. In California, it would be a guardianship of the estate for the minor children.
You cannot get Power of Attorney from someone that is dead. Power of Attorney, if it had been granted to you during the grantor's lifetime, ends upon death of the grantor.
If the deceased is gone, you can ask to be appointed as administrator of the estate in the probate court. But, any family member of the deceased may have a better chance as the law recognized next of kin in VA.
You can only get a POA when someone is alive, and they are only valid while they are living.
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As other attorneys have noted, a power of attorney is only helpful when an individual is alive. If your deceased partner prepared a will before his passing, the terms of the will govern who will get his assets. If he did not have a will, then the assets are distributed pursuant to Virginia statute. In this case, it sounds as though he is unmarried but with children, in which case all of his assets will be divided equally among his children.
If you as the surviving parent are caring for his minor children, then there are ways you can have access to these assets for the benefit of the children. The steps you need to take will vary depending on the age of the children and the value of the assets. You need to see an attorney familiar with estate administration to give you a sense of where to go from here.
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