You can tell her that when the body and mind undergoes wear and tear through the journey of life, the soul goes to God to rest for sometime and then return in a new body and mind.
If we have lived life well then there is a constant progress and the conditions of birth are better. But if we have wasted our time and misused the faculties then we come back under more challenging and difficult circumstances.
So death is a mechanism of nature to facilitate our transition from one body to other (as the body tends to become weak and diseased with age) and to give us fresh opportunity for progress through rebirth.
Affectionately,
Alok da.
