"Thursday's Child" is a particularly weak episode of "Murder, She Wrote" for a couple big reasons. First, it attacks the memory of Jessica's beloved dead husband...and that felt terrible. Second, and more importantly, the killer in the story ends up confessing...even though there is no concrete evidence she did it!
Nancy Landon is a desperate and awful woman. Her son is accused of a terrible crime and to get Jessica's help, she tells her that the son was fathered by Jessica's dead husband! Tacky and cruel? Yep. But it does manage to get Jessica involved in the case. And, in the end, the REAL villains are discovered...and the killer ends up confessing when common sense says the police didn't have nearly enough evidence to arrest her.
Overall, an episode I really disliked...as did my wife who watched it with me.