Hi there,
I think it sounds fine at this age
Its great she drinks it quickly, and 3-3 1/2 ozs sounds good to me
Also the 2 night feeds are about right, I would expect that for a good while yet.
I would say she refuses more because she has had enough. Signs she is ready for more milk would be that she drains the bottle and continues looking for more milk and displaying hungry cues and that she displays feeding cues before the "normal" time she normally wants to feed.
She is still so tiny and it sounds like she is doing all the normal things, so I wouldnt worry right now