Are you raising your grandson as well?  I can’t believe that her Aunties are so cruel, I would think the love they had for their sister would extend to her child.   It’s not like CAH is contagious!  I would flat out ask them why she is not included...make them voice their stupidity.  That just ticks me off! 

I have to admit, with all the head butting I do with  my mother & sister regarding my daughter,  they both love my daughter & she is included in everything.  Your granddaughter is in my prayers

jess