"Of Course they'll take care of my wife...."

Um....as wonderful as they may be, there is no surity here. I'd invest $13 and a few hours and read this book for some very eye-opening stories...true stories....

http://www.amazon.com/s/ref=nb_sb_ss_c_1_16?url=search-alias...

They could marry and be strongly swayed by the opinions of their husbands. They could need the money for their own financial woes. For their own children. One of them could get sued and the money taken in the suit. They could decide mom is bat-spit crazy and use a small amount to put her away...

The best way to protect the interests of someone who is gullible or mentally ill is to create a trust and have a trustee (a professional, not a relative) dole out a pre-determined sum on a regular basis after your death (assuming the sum you will leave is large). The trust protects the money from scam artists (except in small chunks) and greedy kids and lawsuits and the like....the book above will explain more.

Best of luck.

SG