If the parents are not on board then you are certainly more limited in what you can do...BUT it doesn't mean you can't do anything.

You can still take notes and observe to see if you can gain more information. You can try and provide different coping skills etc. It doesn't have to be directed at this one child...any and all children can benefit from learning about such coping strategies.

You likely won't have a great deal of progress if she is starting school in the fall and the parents are not on board but it will still be useful.

I would just again caution that if it is anxiety causing the repetitive words then I wouldn't force the child to stop or punish the child...it is not the same as trying to curb a bad behavior. Too much pressure to stop saying the words to release anxiety will end in the use of other coping strategies (which may be worse than repetitive words).

Hopefully the school is able to work with the family to acknowledge it is beyond the scope of 'normal'.