S1T1E1P3S1I1S1T1E1R1
12 points
STEPSISTER is validvalid
a daughter of a stepparent [n STEPSISTERS]
a daughter of one's stepparent by a former partner [n -S]
a daughter of a stepparent [n STEPSISTERS]
a daughter of one's stepparent by a former partner [n -S]