Advice about repetitive behavior?

Mom prays her rosary from waking to sleeping. 10 or more hours a day. She has dementia mild to moderate. She is 98. Has cateracts and severe hearing loss. She has begun praying her rosary without actually having one in her hand. She has a far away look on her face. She fingers the beads, pulls at it, untangles it, looks at it . Should we let it go or give her an actual rosary. I don't know if we need to keep her in the present or allow her to go into this other realm. We do understand she is escaping because she can't hear or see. We have begged her to get hearing and vision corrected but she refuses.