HUGS!
Willow can still be Willow (it is a gender neutral tree after all) and Flora can still be Flora if that is what they are for you!
There ARE sows called George and several boars called Lily...
As far as your piggies are concerned, they have their own identity whatever you call them.
If you wish for a more gender appropriate name for Flora and don't like Florent, Florian or Floriano, perhaps another tree name like Rowan might feel better?
But there is no hurry in re-naming. Your piggies are still the same. If you let them, they'll rename themselves with an endearment or nickname anyway! Some name will stick, whether that is the old names or new names.
Please take a deep breath! Your piggies are still the same personalities that you have brought home. They haven't changed one bit. They are still exactly as lovable as they were this morning.
They are going to create their own piggy shaped space in your life that was never going to resemble your ideal dream image, whatever the gender. Piggies take matters in their paws and turn your life upside down until it fits
their ideas how
your life should be anyway! No matter whether they are girls, boys or one each.
PS: I am very glad though that you have two of the same gender and that I am NOT going to see you in the pregnancy section which is a whole different can of worms! Piggy mis-sexing is sadly anything but uncommon.