In a high needs school in particular, it may be helpful to acknowledge the needs which the teacher is already challenged to support--children at-risk with regard to food insufficiency, housing, family supports, etc. in addition to academic delays--and, if possible, to offer any resources you may have available (e.g., volunteering as a parent helper in the classroom occasionally, supplementing soft classroom needs such as extra facial tissue, pencils, etc. which are often purchased out of pocket by teachers), not only because this would be a compassionate thing to do, but as part of the process of building an alliance and collaborative relationship with the teacher.
At the same time, one may be clear in drawing parallels between the needs of children whose instructional needs fall above and below that presented in the standard core curriculum, who are equally at risk of becoming disengaged with the educational process, and consequently not blossoming to their potential.
I will additionally note that the first month of school is typically when teachers are collecting a fair amount of RTI/grouping/intervention data on incoming students, so there may be a lot of assessment demands on her right now, and precious little time for even middle-of-the road instruction, let alone differentiation in either direction. She may not be putting you off, so much as scrambling to stay ahead of all of the administrative requirements imposed on her, some of which may even be cited in her personnel record if she cannot complete them by an arbitrary deadline.
My thought would be to do your homework on advocacy in your state, so you feel confident going into any conversations with the school, but also allow some grace for the constraints under which the educators in the system may be working. One may be assertive without being adversarial.
