"While there was no overcrowding in Darroch Hall and Chrisswell House, overcrowding in Ailsa Hall was approaching 100% and sometimes three prisoners were sharing a cell."
On the impact of the problem, he added: "This overcrowding means that staff have limited time to deal with prisoners and that there are not enough work places.
"Many prisoners in Ailsa Hall have an empty day, with prisoners on remand and on protection having the least opportunities to take part in useful activities."
The corresponding figure for Ailsa Hall last year was 69%.
Despite the criticism Dr McLellan did describe the overall report as "encouraging".
He said: "It was noticeable that the prison had drawn up an action plan in response to last year's report and almost every matter raised in that report has been addressed successfully.
"There is now a full programme of work and activities for the women transferred to Darroch Hall last year, and relationships between the prisoners and staff there are good.
"Long term prisoners in Chrisswell House have the opportunity to access good work placements and home leave and are working towards open conditions."
He added that induction and participation in programmes was "less satisfactory" but welcomed the fact there had been no escapes since the last inspection, no suicides in three years and levels of violence were low.
A full inspection normally takes place every three years and examines all aspects of the establishment. Follow up inspections take place every other year.
The inspection of Greenock, in March, was a follow up inspection with a focus on conditions in which prisoners live and on the way prisoners are treated.