I've not collected my results yet.. but I expect to get all As or Bs... I think the exams are getting easier, but I don't think that is the sole reason for this '1 in 4 gets an A grade' statistic.. these stats don't take into account which subjects have been taken, some are considered easier or harder than others. Although, I guess they are difficult in their own way. E.g. I'd flop at media studies whereas I'd do well in a science.
Besides, the main reason I think is that access to information is much better than it was previously. With the internet, people can look at dozens of past exam papers with a click of a button. So students taking exams get more practice and just.. get the lay of the land, and hence passing the exam with a high grade is just a case of practicing enough beforehand or revising mark-schemes.
The exam syllabuses themselves are somewhat easier in comparison to the syllabuses taught before our generation, but I don't think that has as great an impact on the no. of A-grades in comparison with the level of information students can access nowadays.
Resits are also, lol
As for girls outperforming boys well.. I dunno.. perhaps it's genetic. XX > XY.