In a case about a nanny who didn’t receive overtime pay despite allegedly working 79 hours a week — with a 23-hour shift and four 14-hour overnight shifts — a district judge granted the parents’ request for summary judgment based on the Fair Labor Standards Act’s exemption for domestic employees who “reside” with their employer.The exemption applies to “any employee who is employed in domestic service in a household and who resides in such household.” 29 U.S.C. Sec. 213(b)(21). Answering “an important question for both …