The sentences referred to below apply to first-time offenders convicted after a trial. An early guilty plea can lead to a reduction of one third in the sentence. Previous convictions can push the sentences higher. Judges are obliged to stick to these sentences unless there are genuinely exceptional circumstances, which must be explained in open court.
GBH with intent is a very serious charge, which is close to 'attempted murder', and carries the same maximum penalty of life imprisonment. For the lowest level of assaults which justify such a charge (i.e. where there was no premeditation, no weapon was used and the injuries were not life-threatening, very serious or causing permanent disfigurement) the 'starting point' sentence is 4 years imprisonment; the judge is allowed to pass a sentence within the range of 3 to 5 years.
But stamping on your head (while wearing stilettos) will be regarded as 'using a weapon'. That moves the starting point to 5 years, with a range of 4 to 6 years.
Further, if the court regards your injuries as 'particularly grave', the starting point is then 8 years, with a range of 7 to 10 years.
With a good barrister, and an early guilty plea, your attacker might get a sentence of '4 years minus a third' = 2 years 8 months (of which 1 year 4 months would normally be spent 'inside'). But a sentence closer to 4 years is probably more likely.
It's not impossible that, in the interests of the child, the court might impose a non-custodial sentence but I'd regard that as extremely unlikely. I'd expect the offender to be 'out of circulation' for at least a couple of years.
Chris