All models except for Female_Adult_16 and Chef_Female_01 have a material with a name following the pattern <1-2 chars><3 digits>_head. Female_Adult_16 does not have a head material at all, presumably because the model is quite special.

In fact, Female_Adult_16 has only one material, named f204.
In contrast, Chef_Female_01 does have a head:

This model has two materials: f110_body and f110_A_head. Perhaps it would be better to rename f110_A_head to f110_head for consistency?