good deeds

Parents receiving the reward of good deeds carried out by their children

Q:

1- In a bayaan it was mentioned that the parents receive on going reward from their children after the parents leave this world. Please explain whether this is correct?

2- A brother (who has children and their mother, has passed away) asked if the good deeds his children carry out will be rewarded to the woman who he marries , because that person will play the part of a mother?

3- Also if the brother marries again and if the new wife gets the reward of of his children, does that effect the reward for the real mother of the children who has passed away?