The Middle Ages by Jennie Fields
Jane is the right side of fifty, happily divorced, the proud mother of beautiful, gloriously teenage twin girls, the owner of a stunning house in Brooklyn. She is long-established in her job at a big firm of architects, and has no desire for a partner to share all this with. But when she is unexpectedly made redundant, and a bored-moment Internet search turns up the address of her first love, Jane's future is suddenly a big unknown...