Hi and welcome:
Have you considered looking into other school districts? Things are done differently , and if you like what you see maybe you can advocate for a district transfer? After all Seattle is not a small place ;-)
You should test your kids to know where you are standing, but the most important thing here is your gut feeling. Is it an option for you to take your 13 year old to a high school for a higher level course? Would the school consider for her to take some classes online? Look into Aleks for some math help for both of your kids. I can't stress enough how important Aleks has been in math education for my daughter.
Are you far from Belleuve School District? Check out this site
http://www.bsd405.org/default.aspx?tabID=335Ania
