setting children in secondary school - fiddling the numbers to achieve a gender balance...

[harpsichordcarrier]

This week I have been listening to, and participating at the margins, in setting discussions - year 7 into 8, 8 into 9 and 9 into GCSE.
In almost every case, children have been moved around the groups to achieve a gender "balance" because, in practice, the top sets would be heavily dominated by girls and the bottom sets by boys.
So boys with lower achievement levels/potential are put into top sets than more able girls, and relatively able girls are put into bottom sets.

This seems to be accepted practice but I am very about it. Why shouldn't a top set be mostly/mainly girls? Why should that matter?
opinions please

Moving a child up does usually mean moving one down as otherwise you end up with 40 in the top set and 5 in the bottom! There is some flexibility but it is to noones advantage to let classes become overbig. Generally end of year set changes will involve moving 2 or 3 children up rather than 1 which is of course more noticeable. I have also found that new entrants to the school usually go in high sets where numbers are already big. You have to have some flexibility to allow for this too.

My DD has SN, and is currently in the lowest sets for everything. Despite having made massive progress this year (gone from lvl 2c at end of Y6, is now on 4m, equivalent to 4b), they have moved 2 BOYS up to the next set for next year, and, knowing their parents, their levels were 3h(a). So why is my DD, despite being 2 sub-levels ahead of the boys not being moved up? Because the next set up has a high percentage of girls.....My DD is distraught, as she has worked bloody hard to make that amount of progress, and she feels like she isn't being rewarded for that. THAT'S why I think the 'balance' thing is waaaaay overrated.