We do cover Chelmsford and the wider Essex area at Capstone, so I can speak to this directly. We work with foster carers across Essex, including Chelmsford, Brentwood, Harlow and Colchester, and our Essex team offers 24/7 support to carers.
In terms of foster carer groups specifically, I would not want to give you details off the top of my head because what is running locally can change, and I would need to check what is current in the Chelmsford area rather than tell you something out of date. Essex County Council sometimes runs or funds local support groups for carers independently of agencies, so it is worth asking them directly too.
The Fostering Network (thefosteringnetwork.org.uk) also maintains connections with local fostering communities and may be able to point you towards peer groups in your area.
If you are already fostering with another agency, your supervising social worker would be the best first port of call for what is running near you. If you are not yet fostering and are thinking about it, I am happy to answer any questions here about the process.
I work for Capstone Foster Care, an independent fostering agency. My response is only applicable to fostering with Capstone.