I believe 9 months old is too young to potty train. My daughter is 11 months old and has been fighting changes since she was 8 months old because like the car seat and high chair it is holding a "busy body" in one place and they want to be on the move not patiently waiting for you to change them. Pulling at their diapers because they can now. Its all part of starting to be independent. My nieces/nephews all were not trained until they were almost 3. I definitely plan on my daugter being way sooner than that but to expect her to tell me now before she has reached other major milestones would get in the way of her concentrating on walking, talking, reasoning skills. My mom also said she potty trained my sister at 10 months and brother at 1 year and they were bed wetters until they were 10 years old.
Sorry so longwinded. Just had some thoughts.