So with BLS, if bub is allergic to something, will she still happily eat it?

I've started to think DD's fussiness might be an allergy, especially after seeing her green poop last night. It could also explain the sudden onset of eczema.

But all she's tried is parsnips, avocado, potato, wholemeal bread and banana.
I think the only likely one here could be gluten, from wholemeal bread.

My diet has been pretty much the same as hers, and nothing new or unusual.

But I thought with BLS, that Bub will only generally eat what she knows she can handle..
WDYT?