Aurelia Arrietty - I love this but it is difficult to say.
Aurelia Lyonesse - I like this!
My suggestions would be: (I think these names should hit all three of the requirements you listed, without repeating Iris).
Aurelia Ash (Ash is the god of the oasis and the vineyards of the western Nile Delta)
Aurelia Hebe (Greek goddess of youth and also a genus of plan in New Zealand).
Aurelia Minthe (Greek Naiad nymph who was transformed into a spear-mint plant)
Other suggestions: Lotis, Heliades and Daphne
I like a little longer middle names with Aurelia
For flow I like Aurelia Guinevere
For overall prettiest I like:
Aurelia Arrietty - who cares if it's hard to pronounce? that's what middle names are for
Aurelia Artemis - easier pronunciation
I also like
Aurelia Calista F
Aurelia Juliet F
I've listed some mythological and botanical names below, some familiar and some a bit more unusual;
Aurelia Nerise (a derivative of Nerissa, a sea nymph)
Aurelia Echo (my favourite - unusual, but still familiar)
Aurelia Helen (of Troy)
Aurelia Nyx (Greek goddess of night)
Aurelia Eirene (Greek goddess of peace)
Aurelia Daphne (a fresh water nymph)
Aurelia Circe (Greek goddess/witch depending on what version you read. Pronounced the same as Cersei Lannister in the Song of Ice & Fire series in case that bothers you. She's not the nicest of characters!)
Aurelia Niobe (a princess in Greek mythology)
Aurelia Danae (one of Zeus’ mortal lovers and the mother of Perseus, who killed Medusa)
Aurelia Hermione (Helen of Troy’s daughter)
Aurelia Clove (also a Hunger Games name)
Aurelia Myrtle (a family of evergreen plants native to Australia)
Aurelia Rue (another favourite middle for Aurelia. Another Hunger Games name)
Aurelia Guinevere is my absolute favourite!
I really like the suggestions of Echo and Celandine too!
ha ha my name is Sorrel :)
Ok so after another discussion with DH the list consists of the following..
Current Serious Contenders (that feel special in some way):
Runners Up ( sound nice but don't feel like I have a real connection to them):
So typical that most people's favourites are the ones I feel aren't significant in any meaningful way! Lyons is a family name, Celandine is a type of buttercup and so she would have a flower fairy picture like Iris plus the beautiful meaning of 'golden buttercup', Nimue has been my favourite name since I first started loving names (along with Iris' middle Ophelia) and Fern I have liked for a long time too (problem is meaning is 'golden fern' which to me would be a dead fern...am I reading too much into it?).
We don't plan on having any more children so I suppose I am feeling like I need to make the most of my last naming opportunity...
Any other thoughts?