Sharon,
Here are the 4 inscriptions (not necessarily in the exact order that they appear on the stone but put into a family group to avoid confusing generations).
"Robert Crozier died 24th December 1898 aged 79 years. His wife Margaret Menzies died 8th December 1898 aged 80 years. Their daughters, Isabella died 17th March 1853 aged 7 years & Margaret died 29th February 1876 aged 22 years".
Adjoining stone -
"Erected by his sons in memory of Archibald Crozier who died at West Quarter 29th April 1863 aged 53 years. Their mother Margaret Scott died 17th July 1897 aged 79 years. Their sister Helen died at Paisley 11th October 1889 aged 49 years. John died at Johannesburg 17th March 1890 aged 41 years. Margaret died at Saltcoats 7th June 1890 aged 52 years. Willie died in infancy. Eliza died at Rutherglen 20th February 1901 aged 55 years".
"William Shearer died at Sidehead farm Stonehouse 16th November 1931 aged 80 years. His wife Janet Crozier died at Auchmeddon, Lesmahagow 1st November 1910 aged 62 years. Stone erected by their son John".
And in the new cemetery extention -
"John Crozier died 28th April 1932 aged 84 years. His wife Helen Shearer died 23rd September 1934 aged 81 years. Their children, Private James Crozier H.L.I. died of wounds 10th May 1919 aged 19 years. John Shearer Crozier died 22nd May 1934 aged 41 years. Janet died 4th April 1969 aged 80 years. Agnes died 7th June 1972 aged 86 years. Elizabeth died 26th December 1973 aged 90 years. Christina died 8th December 1980 aged 84 years".
According to the Commonwealth War Graves Commission, the above James who served with the HLI had the middle name of Brownlie - a good match for you! Here is the link to the website -
http://www.cwgc.org/find-war-dead/casualty/666649/CROZIER,%20JAMES%20BROWNLIESancti, a member of this List, may well have photographs of the stone at Glassford (The Glessart as it's known locally).
Lodger