For me the mother's nationality would play a big role. If the mother is french I prefer
Veronique and if she's spanish I prefer
Veronica.
I think
Agnessa Veronique or Agenssa
Veronica have a better flow in each of the sets.
I wouldn't use
VeronicA Agnessa because of the clashing "A". If you want to use
Agnessa as a mn, then I'd definately use
Veronique as a fn.
I prefer the
Veronica spelling. The K makes it somehow more trendy. Spelled with a "c" it seems more genuine.
I like both the names individually. If
Agnessa is pronounced correctly I love it, but I rather suspect there would be some problems there. I like
Veronica as well, but I prefer
Veronique.
Lea