Clue #1:

The death of Fifi Flemington leaves you as the last sister-in-law standing. You’re not sure why anyone why anyone would want to kill Fifi. But, now that it’s been confirmed that the competition was rigged, the rumour you’d heard about the recent changes of business inheritance is starting to make sense… 

On an unrelated note, you can name a hundred reasons why someone would want to kill your of a husband Dick: the idiotic words that spew from his mouth, the way he chews with his mouth open, the way he prances around on that hobby horse…just to name a few.