is it worth it for my widowed mother to transfer her deed to her home to her only son to protect it from medicaid?

The transfer will not "protect" the house from Medicaid.  If she needs full time skilled nursing care in a nursing home, she will have to pay for that care.  If she runs out of money, the house will have to be sold, and then the money spent, month by month, for her care until it runs out, and then if she still needs care, but has no money, medicaid will pay for that care.  She will be in eligible for Medicaid if she has transferred any assets within five years of applying for Medicaid.  So if you transfer the house you are basically gambling on the chances of her being able to stay in her home and/or pay for the care she needs on her yearly income plus her savings for five years, or until she is 95.  As an elder law attorney, I would advocate using her assets for her care.