Question: Is specifying three days for the paying of condolences considered an innovation? Is there paying of condolences for young children, elderly women and ill people from whom one does not expect intercession after their death?

Response: Giving condolences is sunnah as it strengthens the one afflicted and contains supplications for what is better for them. There is no difference in this matter between the deceased being young or old. Furthermore, there is no specific expression that one should use. Instead, the Muslim consoles his brother with whatever expression seems suitable at that time, such as saying, "May Allah make your grief easier and forgive your deceased." This is if the deceased were a Muslim. If the deceased were a disbeliever, then supplications should not be made for him. One only consoles for his Muslim relatives with the words above.

There is no specific time for it, nor any specific days. It is legally sanctioned from the time of death, before Funeral Prayer or afterwards, as well as before the burial or afterwards. It is best to do it soon after the death when the affliction is still strong. However, it is permissible after three days of the death since there is no evidence to restrict it [to the first three days only].

Shaikh ibn Baz

Islamic Fatawa Regarding Women - Darussalam Pg.134