The U.S. Department of Labor (DOL), in Administrative Interpretation No. 2010-3, has expanded the definition of son/daughter for the purposes of childcare leave under the Family and Medical Leave Act.  Under the FMLA, eligible employees are entitled to take up to 12 weeks of leave for the birth, adoption, or placement of a child or to care for a child with a “serious health condition.”   FMLA regulations state that “son or daughter” includes a “biological, adopted or foster child, stepchild, legal ward, or a child of a person standing “in loco parentis” (in place of a parent).   “In loco parentis” includes those with no biological or legal relationship with a child.   According to the Administrative Interpretation, an employee qualifies under the “in loco parentis” test if: 1) S/he provides day to day care for the child OR  2.) S/he is financially responsible for the child.  Additionally, an employee need only provide a statement, that day to day care or financial support is provided, to qualify for the leave.  The DOL’s Interpretation can be found at: 

http://www.dol.gov/whd/opinion/adminIntrprtn/FMLA/2010/FMLAAI2010_3.htm

The Interpretation expressly mentions same sex couples as qualifying for this leave.  It could also include grandparents, siblings, aunts, uncles and other family members or friends. 

Note, however, that the FMLA still does not require leave for unmarried employees to care for their seriously ill partners.