The best advice I could give you if you're struggling to get the tests you need booked is to contact PALS at the hospital to help you.
Babies in general have pretty awful vision and the rate that it improves at varies immensely - some take much longer for the visual system to mature than others. But at 9 months all babies have much, much less good vision that children a couple of years older than them.
She may have optic nerve hypoplasia, but all that means is that the area where the fibres containing the information from what she sees, which then travel to the brain, is not formed as well as it could be. People who have that condition can sometimes have near normal vision or can have fairly poor vision, it varies.
It could also be that she's very longsighted, the optic discs/nerves of longsighted people often look very flat too.
I'd concentrate on getting the tests that you need done, the fact that her development is fine and also that she hasn't got a strabismus (squint/turn in the eye) or nystagmus (wobbly eyes) is very positive and it may turn out to be nothing to worry about.
I'd also concentrate on her visual stimulation - mammalian eyes only develop with stimulus and at 9 months her best focus is still fairly close to her. Make sure she's not in sling, lots of picture books, colours and textures are ideal.