2% of sexual crimes is committed by women
That statistic is unlikely to be accurate in terms of actual offenders as opposed to convictions. The current definition of rape is gender specific - the offender must possess a penis. Various studies show that a proportion of women admit to forcing men to have sex with them but, as the law stands, this is not rape. Research suggests that men are less likely to report sexual assaults than women, particularly where the perpetrator is a woman. There is also some evidence that women are less likely to report sexual assaults by women than sexual assaults by men. We know that over 15% of sexual offences against children under the age of 6 are committed by women. The idea that "women don't do this shit" is rubbish.
I am surprised at the judge's statement that courses for sex offenders are only available for men. I do not believe that is correct.
Looking at the sentencing guidelines for this offence, it is difficult to be certain but the descriptions in the press suggest this was a category 2 offence for which the sentencing range is high level community order to 1 years' custody with the starting point being 26 weeks custody. The judge should then look at factors that increase culpability (of which there are at least two in this case - abuse of trust and the large age gap between victim and perpetrator) and take into account aggravating and mitigating factors before determining the sentence. As she pleaded guilty "at the door of the court" the sentence would be reduced by 10%. Note that any custodial sentence would probably have been suspended as this appears to be a first offence and the sentence would have been less than 2 years.
Without having seen all the evidence it is impossible to know what aggravating and mitigating factors were present. However, judges should only go outside the sentencing guidelines in exceptional cases. Personally I do not believe there is anything in this case to justify going outside the guidelines.
Overall I think she has been very lucky. It would not surprise me if the sentence is appealed.