What fm u use previously?
U can try asking for sample to let ur LO try too, many companies offer a tin of 400g of fm for u to let ur LO try.
If transiting from stage 1 to stage 2, try giving her pure stage 1 again and see if she take. Than mix stage 1 and 2 and see if she take.
From there than u know where went wrong, it's a trial and error thing, as some baby prefer stage 1, hence transiting is a bit slow and difficult.
Dun worry, u can feed stage 1 till later stage but u cannot feed stage 2 earlier if didn't hit 6 months. So if she prefer stage 1, than have to slowly transit over.
Priya Loshini