If she had shared nude photos of the women on pornhub with no identifying information - or printed them out and stuck them on a lamppost with no identifying information - she would rightly not have got a prison sentence.
The nude photo is just one part - she ran a persistent campaign of harassment and abuse against a woman, the woman's husband and the woman's daughter involving sharing their personal contact details with strangers who were then encouraged to harass them.
She refused to stop even when given first warning.
She plead not guilty in order to force a trial.
The punishment is rightly greater if you refuse to acknowledge you have done something wrong and continue to do so even after being explicitly warned.
I still don't think we should put non-violent offenders in prison for long periods though. I'd suggest one month to give her a bit of a scare and then three years of electronic tagging, forcing her to be at home from 7pm to 7am and either at a pre-agreed place of work during the day, with some of her earnings taken to pay a fine to the victims, or if not employed or in full time training, attending community service for working hours. Weekends/non working days spent tagged at home bar a couple of hours for errands.
Punishment through lack of liberty but also still working and paying taxes or contributing through community service. Much more likely not to reoffend and also much cheaper than prison.