My husband and I will be filing chapter 13 bankruptcy next week. I inherited $20,000, along with each of my brothers and sisters each inheriting the same amount. However we cannot touch the money, which is all in a cd, until my mother passes away. My father requested we leave the money as it is and give my mother, who was divorced from my father many years, $300 dollars a month, which is the interest earned each month, to assist her with living costs.
My brother is over the account and sees that the $300 is given to my mom each month. Since I cannot get to this money do I need to let my lawyer know about this inheritance which I cannot touch since it is shared with 4 other sibs.

Shouldn't you be asking your attorney this question? Assuming you are in the US Bankruptcy laws have changed and can be complicated I think you have to disclose all finaces in a bankruptcy case

If you received the money, yes they bankruptcy court will consider it your money, in fact it may stop you from even being able to file since you are over the exemption amount for cash.