My experience has been that most of what goes narrow - usually stays more narrow than I would like. Guess it's a wait and see. Sometimes they spring, but alot of mine (that go narrow)have not sprung enough for me.
Wait and see how she looks at 12 months old - she is going to go through these ups and downs for quite sometime... so dont get discouraged.
Maybe check out her pedigree/breeder and see if her littermates are going through the same thing, and what the maturity age for your breeder's bitches are.