This sister has taken everything into her hands since my mother died. In Maryland, she is no longer a POA since my father died recently. The POA also died! So what could be her reason for not including the other two children in the funeral planning? She likes "control".
As for the funeral...the family could not agree after my Dad died, so he had 2 funerals, which made everyone happy (sort of).
I don't know what the family dynamics have been so it is hard to say why she went ahead with this on her own. It may be her own need for control, or it may something else, like wanting to do what is expedient to get it over with, or feeling that no one helped her with other tasks, or desire to do things exactly the way Dad wanted them ... or who kows what other reasons? Have you asked her?
Regardless of her reasons, go to the funeral and let the healing process begin.
Do you mean to say that your brother convinced your Mom into giving him financial POA - or be the official executor of her estate? That would have to be done with an attorney. Maybe you could speak to the attorney and tell them that your brother is abusing your Mom's finances and doesn't give you a cent for ALL the work you are doing and he is doing nothing. A medical POA can be done with your Mom's living will--on your own--[but she must sign it] you don't need an attorney to do this medical part. My brother is executor of my parents estate [Dad did this with the attorney long before he passed] while I have medical POA because it is me who took care of Dad before he passed and is still taking care of Mom. Gosh, there must be something you can do, because you are being abused just as your Mom is. Is there free Legal Aid in your state that you can get free legal advice?
I don't know why your sister is not including the most important people in your lives at this point. Usually, there are two people who have POA--two for financial POA and two for Medical POA - just in case something like your situation arises--which it has in your life. In our family, we have two for each--"back ups" in case something like this happens, which it does.
Who has been caring for your parents all of this time? Her or you? Or who has been making all the financial and medical decisions for them all of this time?
Did your parents make a living will before they passed? You must have an attorney to make a living will and empower an "executor" of their estate. Whoever is the executor of your parents estate, that person is the decision maker. If they did not make a living will, or appoint a financial POW or medical POA, then you must have a sit down with your sister and find out what's on her mind and why she is doing what she is doing.
This is a very stressful time for all of you, and yes, as mameformom said, it can bring out the worst or very best in families, but stress is the main emotional conduit by which wrong or very hurtful decisions are made. I believe that ALL OF YOU be involved int he decison making process. That is what we did--my other two siblings. First, we had a sit down with our financial adviser--he said that its critical that the 3 of us be on the same page before anything happens to Mom and Dad. So that when that "time" comes, we are not stressed and overloaded with unanswered questions of what must be done. That's when mistakes happen and emotional burdens rises to the surface.
Please try to communicate softly and with compassion with your sister so that you two can connect with love and not resentment or power controlling emotions.