The previous saint had a revelation in front of lavigne and said that the new saint has brown hair and pink eyes thats why lavigne knows igs esther
Yeah but it's too radon, like she sees ONE girl with brown hair and pink eyes and goes "it must be her" she doesn't even think of looking for another girl because there's only one girl in the whole world with this characteristics
She was suspicious about her in childhood right after she was adopted, but got told the wrong information so she let it go and after the revelation she realized her instinct was right.
It makes no sense for Lavigne making that connection new saint = Dinah/Esther