Hi suesings, is it possible to get a closer photo of the flowers and leaves? Do you know for sure it's a crabapple, i.e. does it produce small bitter apples? If it does, what colour are they?
The flowers look to be pale pink and semi-double, is that correct? It might be a difficult job as I think there's plenty of varieties of crabapple.
If it's possible to find out which varieties are popularly sold in the area your friend lives in in Aus that could also help, location can be very helpful even if it's been bought at a nursery.