I will ask the school on what site they use to show the student's progress.
Due to privacy issue, this is not something the school will allow the public to know and you will probably have to get special user ID and password (permission) from the school before you can access student datat.
I'm sure someone here might know ..but have you tried going directly to the source...the bellevue school district? Call a school district administrator and you could probably get your question answered rather than wait around for someone to read your question and post an answer. ..just a suggestion to get your question answered faster.