I recognize this answer is a bit belated. Two programs in particular can help. One is a Veterans Aid and Attendance benefit and the second is a Senior Living Line of Credit.
On the VA Benefit: If she is a surviving spouse of a veteran or a veteran herself, the VA provides to eligible vets an "Aid and Attendance" benefit. Thousands of communities work with advisors that can help you apply. The benefit can be as much as $1,000/mo or more for assisted living. So if you haven't looked into it yet, please do.
On a Senior Living Line of Credit: Thousands of communities offer families the option of taking advantage of a line of credit for senior living to pay the month to month cost of a loved one's care. Ask your community if they offer such an option. Typically, you can be approved for an entire amount up front, draw it down monthly, and pay it back over time. Typically such lines allow for the entire family to join and share in paying back the monthly payment, so that one sibling doesn't carry the burden. It also enables you to segment your obligation so that it is not co-mingled with your own home equity.
A loan requires you take the entire proceeds up front. A line of credit approves you for a credit limit and you use only what you need as you need it. Be sure to ask for not only the rates, but any penalty rates on the odd chance you are late with one payment, and any fees associated with taking out such loan. A line of credit for senior living can give your family's monthly budget some breathing room, by enabling you to pay back what you used in smaller monthly payments.