Love or Money

I have no trouble reading this book. but I think I have a poor detective ability. I guessed the wrong murderer. the whole book is about the so called money. i do not think they have enough love. Molly loved money so She killed her husband And said it was an accident. Diane wanted the money so She threatened her mother to give her money. Roger wanted money so he tried to persuade his mother to sell the garden... Jakie seemed the most impossible to kill her mother. She did this only For love. Didn't She love her mother? It is sarcastic.