Seems a no brainer to me
Silly question, but, where is dad buried? It would seem reasonable to have her buried with her hubby. Unless she had made a specific declaration for her demise, would that not seem the logical thing to do, given that they were only separated by death, not for any other reason. As for the manner of service, it would seem logical to follow through on her later life. i.e. if she rejected Judaism, but did not embrace Anglicanism, then a civil ceremony, or one in keeping with her current belief set, should be held.
I wonder if the judge ruled for a civil cremation they would come to their senses.
CoE seems like the right choice to me.
Maybe the judge could "Do a Solomon". Cut her in half and let the Son can bury half as he likes, and the daughter could do same.
She was baptized into the Christian faith and did not convert to Judaism. That says Christian burial to me.