In Loving Memory

The inscription on this monument in North Merchiston Cemetery is extremely sad. It reads:
In loving memory of John Aitchison Simpson, died 19th March 1895 aged 16 months. Also George Simpson died 30th August 1895 aged 4 months. Also their father George Simpson, corn merchant, died 19th March 1908 aged 43 years. His wife Jane Aitchison died 24th FEBy (sic) 1940 aged 79 years. 
How much heartache that woman had to go through. Wonder when the monument was erected, and if the names were added on after each family member died or the whole thing was done following the death of the father. The inscription for Jane Aitchison does look as if it could have been added at a later date.