Kestrels are up to 250g, while the female goshawks are up to 1kg (the males are smaller), with a proportionally bigger windspan, so I expect the experts get whacked in the face, and bowled over every now and then.
I don't see why you can't include the difficulties of dealing with a bird of that size, but have your character determined not to give up.
Either that or have a runty male bird (now there's a sentence you don't see very often
)