Thank-you for your advice. This is the first time I navigate a forum (yes, I admit!) and I couldn't figure out how to reply when I was able to read your response.
You were absolutely right, the house was not a problem.
Today we were informed that she would receive an improved pension for $840 if she relinquishes the $133 death pension she receives for my father.
The calculation I was given is the following: her SS is $804, so 804 + 840= $1640, the maximum allowable under Aid and Attendance for a single veteran. BUT, it seems the VA didn't allow for non reimbursed medical expenses (medicare deductible of $1100 and dental of $1500), nor did it allow for the cost of the facility which provides custodial care for $2600. Basically she is going to be short of $1000.
Any ideas? Once again, many, many thanks.