Answer: The McKinney-Vento Act requires the school district and state to remove barriers to retention in school. 42 USC §11432(g)(1)(I). It certainly is a barrier to retention if a student who has recently moved from out of state, and who has all the credits needed to graduate, is barred from graduating. It’s easy to imagine that the student will be at serious risk of dropping out of high school if she thinks there is no way for her to graduate on time. So the McKinney-Vento Act would require some accommodations for her.
One approach would be for the district and/or state to waive the requirement of the state test and provide her with a high school diploma and the ability to walk with the class. Another approach would be to allow her to take the state test, despite the timing, and have her walk with her class even if the test results have not arrived yet. She also will need appropriate support to prepare for the test, as well, since she is new to your state. Another approach would be to get in touch with her previous school in the other state, and get that school to issue a diploma from that district and state. This is a common solution that many liaisons have used.
We’ve worked on legislation in a few states to exempt homeless students from state exams automatically if they change schools in their last 2 years of high school. Unfortunately, your state does not have such a law. But the McKinney-Vento Act’s barrier removal provisions still mandate some accommodation so the student can graduate.