i appreciate that you take this in the spirit that it was meant.
it just sounds like a cruel joke to me
what would be the alternative?
when anyone suffers, they need help to end that suffering, but also hope and encouragement that they will get through it, because some things just can't be fixed with material means.
if you look at this as if there is a god out there that goes: hmm, this family needs a test. how about i mess up their baby?
that would indeed be cruel. but that is not what i believe is happening. i don't know what that particular child suffers from, but by now we can explain many birth defects to some humans mistakenly or intentionally doing something wrong, like poisoning water with chemicals or malfunctioning nuclear reactors, or what not. i don't believe that any of these are pure acts of god. but they could all be prevented if humans as a whole were more diligent. (i don't mean that any individual could have done anything by themselves, but that as humanity we need to work together to avoid and remove things that cause people to suffer[1])
this is a consequence of free will. bad things happen, because if god were to prevent them, then we would not have free will.
nevertheless on an individual level god does promise that whatever suffering we experience is rewarded in the next life, and that we are all given the capacity to pass the tests that we experience and get through that suffering.
[1] that is in fact happening. we have eliminated many diseases and quality of life on average is improving globally. there is more work to be done, but we are getting there.