She feels different.

They fear they got discovered, that she knows something odd has happened to her mother...

"I think I'm different to my sisters... Amy and the others..." They smile, well at least they now know Andrea feels different... probably she is not a girl...

"Really, dear? Why?" Her "aunt" asks her.

"I... I don't thinks boys are cute... I don't want to feel their cocks inside me."

They smile thinking their theory is confirmed.

"Have you tried telling your mother?"

She nods, "Yes, but she keeps telling me not to be silly, that a cute girl should love boys and pink colour."

"Neither of that is necessary. You can like other colours or love girls..."

"Really?"

They nod "Yes, when your mother was young she loved women instead of men and hated pink..."
"Wow, what a change... What can i do?"
They smile, "Maybe we can give you some money to live by your own so she doesn't impose you anything..."
Her eyes shine and hugs them "Really? Thanks!!"

They smile having solved the doubts. Andrea probably wasn't a girl and is gone. if she feels different probably Amy is really a girl... First couple solved... but the next couples cause the same troubles...

You got angry because of her leaving you but finally accept: you've lots of girls to love and care about... but gets a bit disappointed when Amy asks for the same. Finally she accepts knowing this may happen with time and that more little girls will arrive soon to her.