In Episode 83, Pirena asked Cassiopea who Lilasari's mother is. Cassiopea said she cannot tell Pirena, because even Lilasari's mother doesn't know that Lilasari is her daughter. For her statement to make sense, I thought that Lilasari's mother should still be alive at that point, but there were very few other powerful female characters of note that we know about. If dead characters can be included among the possible mothers of Lilasari, Avria would be an easy pick.
P.S. - I placed this on the blog instead of article comment because I think this remains to be a possibly legit spoiler.