Discuss the assessments that require a verbal response with your OT person or the special education teacher for suggestions on Assistive technology choices. Google has a program called "Speak It" in which a passage can be highlighted and read to the student at different speeds. Also,most assessments which are going online will provide read-to services. Check this child's IEP accommodations to make sure everything is being offered that might be needed.

Another solution would be for the special education department to provide this student with technology to allow them to write their responses. Over time as the OT and speech continues ask them for assistance in developing responses that the student can use to help with their understanding in your classroom.

In middle school we use keyboards for students who have extreme difficulty writing. You may want to try this approach to see if it helps the student. Even though the assessment requires a verbal response, you may find that the student is better able to express herself through typing. This would at least show progress with the student.