Identifying Fledglings

After a windy afternoon, at dusk, I found three little fledglings on the ground huddled together past my back gate - a highly dangerous area as dogs walk there and owls come into the garden at night.  As a temporary measure I put them in a small padded plastic container in the nearest tree.  In the morning I saw from about 100m parents come to feed and care for the birds.  I bought a rafia nest as better protection and transferred them to the same spot, but after that left them alone.  Because I am trying to interfere as little as possible with them I am having some difficulty identifying them.

They are very small, about the length of a little finger, with yellow slightly slender beaks and greyish fluff.  The brief glimpses of adult birds I have seen have been small, fast moving, with slate grey backs and buff to yellow underparts.  I can't get any closer to observe much more than that. I was wondering Gerigone or Fantail?

The area in which they were found is about 100m from a creek, which is thick with privet and ferns and other vegetation and then up the hill turns into a more open sclerophyll forest.  This is in the northern Sydney region.

Would love some help!