Brilliant question! Too many people do something this important without thinking out the consequences first.
I would talk to an estate planner, not just the accountant/cpa/attorney's that everyone else has mentioned so far. This is a very complex issue since what benefits you may not benefit your mom. You need to look at the whole picture and decide from there. You need to look at your tax situation and hers and do the math for each to see what the exact net answer would be. Not all CPA's or Attorney's are familiar with estate taxes, gift tax limits, transfer taxes, etc. Also, make sure they understand this is a non-arms length transfer between family members, that changes the answer too. (For example, when they had the government tax credits for buyers, this wouldn't have counted for the $8K tax deduction since it was between family).
Would you mind letting me know the response you get in the end?
Best of luck!