I (30M) had a startup that was acquired by a private equity firm last year where I ended up with ~$100M post tax.

I set up a trust fund with myself, my parents, and my brothers (33M and 29M) as beneficiaries, where they will each get dispositions of ~$100k/year and I will get ~$500k/year. The trust is set up to be perpetual where each of my and my brothers' children will become beneficiaries when they turn 18.

Now the issue is my older brother is married to a woman who has 2 daughters (11F, 8F) from a previous relationship. They're good kids, but I don't really see them as my family and for that reason did not add them as beneficiaries.

AITAH for setting up a trust where my nieces and nephews will end up with a safety net equal to a middle-class lifestyle while their half-sisters will need to work to have the same life quality?