Could they tell which gender people identified as by the bone fragments, or would that be too much science?
EC
If the bones contain DNA, they can analyze it by PCR for the presence or absence of Y chromosome specific genes.
Depending on how intact bone fragments are, it may be possible to determine the shape of the pelvis, which would show whether male or female.
XX chromosomes cause people to “identify” as female.
XY chromosomes cause people to “identify” as male.
Only rare genetic abnormalities cause males to identify as females and vice versa. The fad of identifying as the opposite gender despite a lack genetic mutations or regardless of the presence or absence of a Y chromosome is just that: a fad which has no basis in physical reality.