@asterel
70k with 2 adults and 2 children and 500 quid in council tax ( indicating a nice house in an in demand area) puts as being in the 6th income decile, so higher than average.
However, this is a bit contrived as we would usually just look at gross income or disposable income.
So lets look at that, 2 parents, equally earning 35 k would leave a household with 56,542 after tax, no pension contributions and no student loan payments ( which is unilkely). Keep their CT at 500, and then we have 6k per year off that.
So 2 parents and two children are going to have 50,542 to live off ( and these are people who are better off than average).
Give them an average mortgage payment for the uk of 700 ( unlikely but we'll go with the average rate, and then we are down to 42, 142. For bills, fees etc. Totally doable to pay private school fees if only one child goes, it might be a stretch but that gives an income for bills/food/holidays etc of 24142 or 2011 pounds a month.
Now can this family possibly flex their income to find the extra 225 quid a month for one child? Quite probably. Again its a stretch, but probably.
If they wanted to educate 2 privately they never had a chance of achieving that on this income.