Is it recommended to inform one's mother and siblings that one is supplicating for them, knowing that this pleases them and increases affection?

A Muslim's supplication for their family is desirable, and the prophets, peace be upon them, did so. Informing them of the supplication brings affection and joy, and it motivates them to supplicate for you in return. The supplication of a Muslim for their brother in the unseen is answered.