Dear Future Daughter in Law,Hi. This is me. Your mother-in-law. I have been thinking a lot about you lately. A mom with 5 sons will be prone to do that from time to time. I have many to things to tell you but I will take my time. Since I have a good 12-22 years. And I am not flexible on those dates by the way.
So the first item of business is this...
I am sorry.
I tried.
I really did er, do.
Your husband was taught several million times how to ... do dishes, put his clothes away, clean a bathroom, not burp at the table, take out the garbage, put stuff back after using it and to put the seat down. Really. He is being taught. REPEATEDLY. I hope some of it sinks in before I turn him over to you. 

But if for some crazy reason it doesn't do not curse my name or ever think that I was a lazy mother or any of those other thoughts you will have about me.
If you can't help but think you would have done things so much better then I will gladly sit back and watch and learn as you raise my 5 fine grandsons that I will pray for you to have.
I love you dearly.
More later,
MIL