I forbidding my daughter to attend her uncle's funeral.
What will happen if you forbid your daughter from going to the funeral?
She will learn that by brother was a real jerk in his lifetime.
A funeral is a very important event for people in grief as it allows them a final chance to say goodbye to a loved one. It is wrong for you to attempt to control your daughter by forbidding her from attending her uncle's funeral since it robs her of her own personal choice to attend or not. Whatever happened between you and your brother, you should set aside that issue and let your daughter attend her uncle's funeral or your relationship with her will suffer.
She is not going to that jerk's funeral. Period.
Your daughter deserves to find closure with her uncle by going to his funeral and you getting in the way of that is interfering. Show some respect for your daughter's needs rather than just your own resentment towards your brother.