If I send a client a check for refund on a job I did for them, and they cash it--is it legal binding for no further action

I refinished a hardwood floor job--hired by one woman, and her partner was out of town. She returned and did not like the job that I did. I offered to fix the job, and quickly realized how unreasonable she is, and am choosing to refund her money. If she cashes the check, does that make the business dealings between us final.