Is it permissible for me to intend my charity on behalf of myself, my living parents and sister, and my deceased grandparents, paternal uncles, and paternal aunt?

It is permissible to dedicate the reward of charity to oneself, to one of the deceased, or to all of those mentioned. For every act of devotion a Muslim performs and dedicates its reward to a living or deceased Muslim, it is permissible and beneficial to them.