Autism and Autism can be two extraordinarily different things... It's called a spectrum for a reason.
While what she did was horrible, and additionally trying to abuse racial discrimination in her report, I... Have a hard time saying that it's the most difficult motive for murder to sympathize with.
Someone who kills for pleasure, who delights in the torment and pain of another individual and who ends a life solely for their own entertainment, that I consider to be difficult to sympathize with.
But a person who has struggled for years with a child who is potentially extremely difficult and taxing (even moreso than a more neurotypical child already is), who is already at her wits' end, and is conceivably being met with the being she is biologically programmed to care most about in the world, but who barely even knows she exists despite how much she has to sacrifice in order to care for them... No.
Is it excusable? No, absolutely not. Can I empathize? ....yes.
Yes, kids on the autism spectrum will always be challenging in one way or the other, but in many cases that's perfectly manageable and the unique perspectives and experiences that come out of it will more than make up for the added pressure, but... But sometimes they're locked so deep within themselves that you only ever get to see a tiny fragment of who they are. And everything else is just pain.