Legal Question in Wills and Trusts in California

He is not entitled to know anything until she dies. But as a brother, why don't you just tell him?

Put yourself in your brother's shoes. He knows your mother is aware he does little or nothing to help her or you, she has given you all the power she can as to her money and care, her Trust is changeable so he could be written out of getting any benefits, and he is spending money [European vacation]. Even though he may not deserve much from your mother's funds, he is rightfully worried that you may have used your influence to write him out of her Trust. Would you not want to know what the trust states? Giving him a copy does not mean that you have to give him any answers as to what will happen, etc. When your mother dies he will claim you used undue influence on her; decrease his future anger by giving him some information now.

Do you have to? No. Should you tell him? Probably for the family dynamic and to stave off some unwelcome surprises later. If he is in for half, tell him. If he is in for nothing, definitely tell him.