Is it considered correct to give in charity money inherited from a deceased father who was not responsible for his children during his lifetime, especially given the children's financial need?

Regardless of your father's state of injustice or dereliction, his right to dutifulness and obedience in what is good does not fall away. As soon as your father passed away, all his possessions became the right of all his legal heirs after the payment of debts and the execution of bequests, and your share of the inheritance is a pure legal right, not a gift from anyone. If your statement that your share is an endowment was merely an intention or an utterance without being binding, then nothing is required of you regarding it, and you may dispose of your share as you wish. However, if you uttered something that implies a binding commitment, such as a vow, then it must be fulfilled, and if this money is all that you own, then it is sufficient to give a third of it in charity. Your taking the inheritance or leaving it does not harm your father after his death, but rather, charity given on his behalf benefits him.