Legal Question in Wills and Trusts in California

She needs to start signing with her other hand. If that is not possible, then she would need to establish some other means of making her mark or acknowledging consent. Without any real knowledge of her physical capabilities and mental capacity, I can't really give you anything more specific.

Mr. McCormick is correct. She will have to make a mark. If necessary, have a notary witness and have her confirm with the notary that the mark is hers. Conservatorship is a drastic route, and requires filing papers in court.