Gah! I hate how people characterize Moaning Myrtle in HP fics!!!
Why does everyone insist on seeing her as simply a bucket of tears and nothing else? If they even bother to probe deeper, they a) make her a Hufflepuff doormat and/or b) make her infatuated with Harry. And a doormat.
Please! There is so much more to her than that!
Okay first off:
Yes, she cries. She's dead. You would too. Moving on.
Yes, she got teased in life. That makes her sad, and probably contributes to her tears, but also consider the fact that EVERYONE gets teased. Teasing =/= doormat.
Now think about the last thing she did while alive. She had been teased earlier, and when she heard a boy's voice invading her quiet bathroom, did she huddle in a corner and continue to cry? Nope. She opened the door to tell him off.
And then she died. Did she meekly pass on? Did she stay in her stall and cry? No. She haunted Olive Hornby to make her pay for her teasing. And her haunting was so bad that eventually the Ministry had to step in and boot her back to Hogwarts. (Which, PS, indicates that she's one of those ghosts strong enough to break the bonds that tie them to a single person/object/place)
Nearly Headless Nick admits that the reason that he came back as a ghost was because he was AFRAID of dying. Myrtle tells Harry when he asks, that she started to die, and but that she came back TO MAKE OLIVE PAY. Not because she was afraid, but because she was vindictive.
Once back at Hogwarts, she spends her time flooding her second floor bathroom. Now, crying so much that you flood a room - pathetic. Turning all the taps, overflowing the toilets, and bothering anyone who tries to enter the room - annoying and tricky, not to mention powerfully poltergeist-esque with her ability to affect the material in ways that none of the other Hogwarts ghosts but Peeves ever do.
Once we enter the Trio era, note her scenes. She yells at Ron. She yells at Harry. She flirts with Harry. She spies on bathing students. She resents a flirtations mermaid horning in on someone she is talking to. She bosses Harry around. She again leaves her bathroom and goes to other places in the Castle and even the lake, moving through the pipes much as the Basilisk did. Strong and opinionated much?
Also, note that Ginny had to have been using the entrance in Myrtle's bathroom to get the snake in and out of the pipes every time it attacked in the second book. What are the odds that EVERY SINGLE TIME it happened, Myrtle was out of her bathroom? Pretty bad compared to the odds that she saw Ginny's actions at least once and then just didn't say anything about it.
Are these the actions of a doormat? HELL NO!
Are these the actions of a strong and smart woman who just happened to have a soft side and a lot of trauma that makes her cry? YES.
Myrtle =/= Doormat
Myrtle = Strong, Cunning, and Interesting