Elphaba, I'm cautious. You say "Obviously we don't and can't know the full facts of this case, but isn't it fair to point out that, based upon the information provided here, the information OP has had is disregardable/ignorable?" We don't know that - we may not have the full details in the OP's post, we have not seen the baby, so how could we make an assessment to say 'ignore'?
All a talkboard can do - except in the most egregiously ridiculous cases, or with a baby who is clearly thriving - is to share info, and to suggest questions a mother might ask, to clarify her options, or sources of further info and advice.
This is a baby who may well be perfectly ok but who has consistently fallen down centiles, who has had a period of slow growth followed by a measurable weight loss. That is not, on paper, a baby who is clearly thriving.
Hence my caution, and my usual reluctance to tell anyone that they can just 'ignore' what the HCP on the ground is saying.
I cannot think I have said anything in the least controversial there :)