So I can’t claim any credit for this, it was pointed out by a friend, but Emma’s tattoo looks kinda like the flowers from the Coat of Arms of the Charming/Snow/King George Kingdom. They’re not identical (5 vs 6 petals, no sepals on the tattoo), but I thought it was worth sharing.
There’s also a pic of the tattoo from the Once Upon A Time fansite (http://ouatv1.blogspot.com)