Answer:
Explanation:
Each offspring inherit one chromosome from each set of chromosomes (from both parents), one from father and one from mother. In libby's case, if she inherit x chromosome from both parents, these chromosomes define her sex.
Sex in case of humans,
XX= female
XY= male
As given, Lilly inherit x chromosomes from both of her parents so grew up as a women.
As libby grew up, her sex defines her gender.