Wren or Petra? Sibling for Rui

Big brother is Rui. Should little sister name be Wren or Petra? Rui and Wren sounds cute as a sib set, but stand alone I think Petra is a more strikingly beautiful name. I also don’t want to be on the nature hippie name trend like Meadow, Sage, Rivers, Juniper, etc but I think Wren may be a little more established than those?