Regency bodice ripper cannot remember title or author

[Pollytipsy]

In the 1980,s i read a book about a girl who married her dead husbands son. It was set in England about regency time. The son turns up just as her old husband dies and he thinks she is a fortune hunter. He then sets out to take revenge and makes her is mistress (but obviously its all a misunderstanding and she was is not a fortune hunter and everyone lives happy ever after.Anyone with any clues to who wrote this or the title please

regards pollytipsy