I notice that lair 2865 had a burial on 17th June 1847 of a Helen Aitkenhead daughter of John Aitkenhead a Virtualler of 137 Trongate, Glasgow. She was 6 months old.
Hope that helps if you haven’t already found it.
Looks like the lair would have been bought around 1847 too.
On 12th May 1848 the son of Robert Hunter, Flesher of 232 Gallowgate was interred in lair 2865 owned by John Aitkenhead. Aged 1 year, 8 months
On 26th October 1848 32 year old Agnes Aitkenhead of 2 McNeil street, Calton was buried due to decline. Lair owned by John