Where to look for ESL work and where to stay (Colombo)

Hello,
My Mum is thinking of moving to Sri Lanka having visited several times in the past. She is a qualified and experienced teacher with CELTA, TESOL (ESL) and music qualifications and she has lived and worked as a teacher in Asia for many years.
We are doing a family reconnaissance trip in July / August to try to find some leads as to where she could rent and possibly find work.I am in the process of looking for accommodation for our recon trip in August and I would like to find somewhere reasonably close to where other expat ESL teachers live and/or work so we could network and research options.
Can someone please suggest areas I should look for accommodation and companies we could approach whilst we are there?
Mum is 68, but I don't think there is an age limit for employment in S.L. is there? She is completely fit and healthy so I dont see why this should be a problem, but if anyone knows otherwise, please let me know.
Many thanks in advance for your help,
Jodi