Extremely helpful, thank you all.
Colinsmum, great links on that other thread and I plan to explore them well.
My question now: I think the school is trying to keep the plane aloft right now. My DD10's teachers (team teachers-2 share the job) are trying to figure out how to challenge this very diverse class. I went to talk to them about this issue about a month ago, and mentioned that my DD and I sometimes work Math Olympiad problems. Teachers asked me to send in the book to look at and DD said she overheard them discussing how to use it. Last night she pulled out her math workbook from last year and pointed to a page and said, "We did this today."
So the teachers "get it" (I think), and are trying, but she's still doing work that she completed a year ago (and it wasn't even hard then) and each day she and other advanced students get one enrichment page but not really enough time to dig into it (10 minutes at the desk-work "station") then off to games or computer or direct learning from teacher.
Do I a) take away some of her reading and free time and try to do the enrichment activities (from links such as Colinsmum provided) at home daily;
b) not worry too much because she'll likely be like Ellipses' DD and she's not going to lose her abilities and she's not really bored (probably because very little direct instruction time); or c) go with Coll's suggestion and fight the battle at school to get her into the 5th grade for math (noting here that we are using Everyday Math, which I don't even like, so maybe going up a year in a so-so curriculum is not that great an option).
With respect to option A, I don't want to sour her on math by forcing her to take time away from other things to work on it. As of now she enjoys math.
DD8 is a separate problem....not as proficient as DD10 but still repeating last year's material.
Thanks again for the valuable input, and I hope to hear what you think of the above options!
namaste
