Is what a person offers in financial aid to his orphaned siblings and in-kind assistance to his newly married brother, with the intention of seeking Allah's pleasure, considered charity for which he will be rewarded, taking into account that he may not have anything left to give in charity afterwards? And is it permissible to reckon the reward from charity given to deceased family members?

You are rewarded for helping your brethren. Your charity to them is more deserving and carries a greater reward than charity to others, for the Prophet, peace and blessings be upon him, said: "Charity to the poor is a charity, and to a relative, it is two: charity and maintaining kinship." Preferring them over yourself, as long as it does not harm you or those whose maintenance is obligatory upon you, is a noble character trait. As for giving charity on behalf of the deceased and gifting them the reward of charity, it benefits them by scholarly consensus, and you are rewarded for honoring them and showing kindness to them.