why is it not going to help her? She certainly needs to consider everything, and sadly it has been shown time and time again that the person you are relying on the most is hurting you.
I also thought, as the incidents went on, that its only going to be someone in your house or close family/friends. The ability of one person to do the wide ranging things that have been done gets more and more unlikely the more sources are tampered with - so someone hacking your email is one thing, but someone accessing private photos, never been published shows a different level of competance. And then being able to access medical records - this goes to a completely different level of absolute sackable offence, beyond any stalking/harrassment, if it wasnt someone who you had disclosed this information to.
If I were you I would do as many have said and make a non-emotional chronological list of events and take it to the police. I understand that this is hugely stressfull and really upsetting but when you do it you need to be able to tell them whilst remaining calm and focussed, The fact that someone is accessing your private, unpublished stuff, and make comment on medical issues moves this beyond subtle hidden digs.
If someone close to you is doing this, they may not want you posting online or getting support, so be aware that they may have put a keylogger on your computer so they may know you are on here and try to derail the discussion. Be aware that the original 'argument' with the forum woman may not be related, but when they saw how upset you got as a result of it, or if they for some way objected to you developing support and friendship through social media, they realised that the anonymity of the internet could be used against you to stop you having a life on there. Some people have a vested interest in keeping vulnerable people in that position, and your previous abuse may have some implication here. Using rumours of child abuse is very clever, because it is a horrific crime (as you are well aware) which the news of which travels like wildfire and is one of those things that a great many people have kneejerk reactions to, and often will automatically assume guilt without question. Again, the fact these stories followed you from home to home does again suggest that the source, possibly with an outside accomplice, may have moved with you, as these rumours spread better through a small community via word of mouth than online posts - although as above, anonymity of the online posters, and their ever changing/multiple users can attack from anywhere.
Im so sorry you are going through this, but really urge you to remain as calm as possible and go to the police. If you can screen shot any of this stuff - even go back and find previous stuff, then an IP address may be able to be found.