Hmmmmmm........but op just says her child is the only white one ( although, I agree, if her fatehr is half asian, then well, she can't, theoreticaly, not be classed completely white herself...if you were to be nit picking and all that), but all teh otehr children still could also be in the same minority of being the only ones in their race in that calss...I mean, there could one indian, one turkish, one jamaican, one russian, one polish...and so on child....you get the drift...!
I can see the worry about the minority part..I was always the only child wiht a cleft lip and palate in any of my schools...and of course have experienced some teasing for that...but all in all, it wasn't a problem.
The schools my children are going to are all quite diverse, and a mixture of all sorts of ethical and "class" backgrouds...I think it's really healthy for them.
Also, see, my Kids are actually "whiter" then op's (nitpicking here, and being tongue in cheek...please no one actually belief I woudl really think like that, please)...but they are still not pure Brittish, dispite all being born in the UK, because I am german....so, OP would have been fine if my children were in her childs class, because of their colour....but they could still have german as a first language, I suppose...not that they do...so...would they be acceptable...and is this their country, or are they disqualified due to the fact that they have german heritage....