If she still has times of lucidity, then take her to her attorney and have her specify an "attorney in fact." That is a durable power of attorney for her, and if all agree, could be you. This will give you the power/ability to spend her money on her as she needs, sign for her, open accounts/close accounts etc, even after she is no longer able to make those decisions. She might also designate a health care surrogate, which is a person who will make her health care decisions as her health and abilities fail.

(((hugs)))