You can access the 1939 Register through FindmyPast which is a pay per view site. They also have transcripts of Cambridgeshire baptisms, as Peter has said in post 5, and from these you should be able to compile a list of the children of Agnes Mary with her various husbands. Then, as Peter has said, you need to access the actual parish registers to glean any clues from them that you can, which should be held at Cambridgeshire Record Office or you might be able to access them for a small charge via your local IGI Family History Centre if they still offer this facility. There have been reports that the IGI are going to discontinue this service but I do not know for sure whether this is indeed so.

Janet