Does the reward for ongoing charity (sadaqah jariyah) reach a deceased mother, and when is the reward accounted for, and is the mosque administration sinful for delaying the installation of a water cooler that was donated?

The mosque administration is negligent if it has no valid excuse for delaying the installation of the refrigerator. The benefactor has received the reward for his devotion to his mother, and his mother has received the reward for charity, and the deceased benefits from charity given on their behalf. The exact time at which the reward for charity reaches the mother is known only to Allah, but Allah's grace is vast, and we have a good presumption that the reward will be preserved.