Another ESOL teacher here, in MCPS. We are really stretched right now, so it seems doubtful that this student has a "shadow" based solely on not speaking English. Young students pick up survival English pretty quickly, and kindergarten is a pretty friendly place for a beginning ESOL student (read-alouds, drawing/coloring, hands on activities).
Could this woman be his mother? If she is a known para, and is with him all day, my bet would be on him having some special needs. Good for you for encouraging compassion in your son!