In return for all the care and hardship that one’s parent go through, children should “make charitable contributions and perform good works in their name, and implore pardon and forgiveness for their souls”

...parents endure the greatest toil and trouble for their children, and often, by the time the latter have reached the age of maturity, the former have hastened to the world beyond. Rarely do the mother and father enjoy in this world the rewards of all the pain and trouble they have endured for their children. The children must therefore, in return for this pain and trouble, make charitable contributions and perform good works in their name, and implore pardon and forgiveness for their souls. 

- ‘Abdu’l-Baha  (Table talks in Akka, authenticated by ‘Abdu’l-Baha; ‘Some Answered Questions’ – 2014 revised translation by the Baha’i World Center)