i don't find anything strange in a woman speaking in a softer,girlier way when speaking in front of other people.
girl power aside, here in italy(but i experimented the same thing in france) when we girls talk in a domestic environment,we can use a lower tone, but as soon as we greet someone,or we speak to a "public"(the public can be a single person!),we switch to a higher,more perky tone.
it's a woman thing,we want to be perceived as younger,more gentle. a lower tone can be sexy,but it can be borderline with rough territory and no woman over here wants to be perceived as just out of the cave.
don't you do something similar wherever you live? nice and soft and fresh voiced when in public, a gravelling voiced witch at home????hahahahhahahaha
ciao girls, friday is just around the corner yyaaayyy