Check with an estate attorney. I'm not an attorney, so this isn't legal advice. But, please, please don't have her sign the house over to you or put you on as co-owner without first talking to a good attorney. Not legal advice, but there's an issue of basis value and stepped-up value--the attorney will tell you about that.
And ask the attorney about the house and property still being in her deceased husband's name as well. Laws vary by state. She may be perfectly fine. Or there might be an issue with the husband's relatives asserting a claim on the property. You should inquire about that, too.
Also, if you mother-in-law is still of sound mind, it's possible that a living trust might be a better way to transfer those possessions. Again, ask the attorney.