sibling getting money from parent

I accidentally posted here. Reposted under financial matters category. My mother is 90 and my brother came into town and left three days later with a check for 20k. Her ability to make logical decisions is in question.  My other post included the detail.  I tried to eliminate this posting but was unsuccessful. 

You’ll need to add more info for us to advise. For now, I’ll say if your parent is of sound mind and able to take care of their own finances, it’s their choice what they do with their money including giving it to your siblings. I have brothers, one who regularly gets money from our dad, the other brother does it more rarely. But our dad is of sound mind and is free to make this bad choice, and there’s nothing I can do to stop him. I’ve begged him to stop it, but he falls for every sob story and always will