Distribution of Trust Funds

My Mom passed away last year.  The assets in her trust included her bank accounts and home.  I am the successor trustee.  The money in the bank accounts along with the money from the sale of her home are in the trust.  I put the money 50/50 into two accounts within the trust since my sister and I are splitting the money.  I am distributing the money from the trust to either my sister or myself as needed.  My sister took distibutions from the trust last year, but I did not. 

 

In TurboTax it asks whether the distribution to beneficiaries is based on percentages or specified amounts.  I select percentages since it is 50/50.  It then shows me what the trust income for 2021 is and asks if this was distributed or a different amount.  In my case, it is a different amount.  The amount I as the successor trustee distributed to my sister from her half of the trust funds.  However, when you select that, it asks for the amount distributed in Required Amount (First Tier) and Other Amount (Second Tier).  I'm not sure what that means.  I just distribute funds to her when she asks for them.