Needing help with names!!

We are having twin girls!! We have names picked out for the most part but are struggling with one. Baby a is Avery Rae and baby B is Alexis middle name unknown. Not only would middle name suggestions be great but we can't use the "is" at the end of Alexis. It is masculine in his culture the feminine is Alexas and I'm NOT ok with the "as"!  So what is better Alexes or Alexys.