How much of the total Memory Care paid, privately, can be claimed?

Depends on her primary reason for being in the nursing home.   See IRS - Q&A Nursing homes, medical expenses, and special care costs - are they deductible?  

• If you, your spouse, or your dependent is in a nursing home primarily for medical care, then the entire nursing home cost (including meals and lodging) is deductible as a medical expense.
• If that individual is in a home primarily for non-medical reasons, then only the cost of the actual medical care is deductible as a medical expense, not the cost of the meals and lodging.
• To determine if your father qualifies as your dependent for this purpose, refer to Whose Medical Expenses Can You Include and Nursing Home in Publication 502, Medical and Dental Expenses.  
• Deduct medical expenses on Schedule A (Form 1040), Itemized Deductions.
• The total amount of all allowable medical expenses is the amount of such expenses that exceeds 7.5% of adjusted gross income.

This is a bit confusing. How do you distinguish/qualify the "Primary reason" for being in "Memory Care"? Mom can NOT take care of herself including taking her medications and then needs supervision for her physical safety and security. But she can dress herself, shower (with standby assist) and feed herself (with provided meals).  But they do her laundry, light housekeeping, prepare and serve meals because she's not capable of doing those things safely and properly anymore.  Still, the Memory Care facility breaks down the total cost listing "related medical expense" as a Percentage of the Total Cost?  Seems they (IRS)  could better differentiate between "Hospital", "Assisted Living", "Nursing Home", and "Memory Care" to help us prevent from guessing what is or isn't qualified?