Cognitive impairment is sometimes viewed as a deficit limiting an individual's ability to participate fully in society. Art therapy, in contrast, is a context in which older adults with cognitive impairments (e.g., dementia, aphasia) are positioned as capable, competent, and engaged through the act of creating and sharing artwork. We draw on the concept of the "Third Hand," a practice in art therapy in which the therapist attunes to and enables the desires of the client during interaction. We use this concept to understand how to empower creative work and sharing among older adults with cognitive impairments. We introduce an interactive frame prototype to explore new opportunities for sharing and supporting interaction between these older adults and their therapist. We conclude with a discussion of what designing for the Third Hand means to HCI, including how this metaphor provides a model of empathy and empowerment in design for this population.