My little sister who is now six has been an avid fan with me for years. I used to watch the show when I was a kid and I grew up fine. I am fairly certain so will my little sister. This show is fun, and is far better than quite a lot of the other modern 'kid' cartoons you could have your child watch. Take this from a girl who has seen all the episodes and knows the series well.
Positive message and role model(s):
The Powerpuff Girls promotes little girls to feel better about themselves in a world dominated by male superheroes and just girl power in general. Blossom is a model student in school who studies hard and acts like a mother sometimes to even her sisters. And the rowdiest of the Puffs, Buttercup, knows when she has gone too far and an episode titled 'Make Zen to Me' is even dedicated to her finding her inner-peace and a much more soothing nature.
Okay, so cartoon blood can get pretty graphic sometimes. But kids do need to know every way to solve a problem. Sometimes asking nicely when your lunch money is stolen doesn't fit the bill. All violence is for justice, however and the prevention of much more violence if the Powerpuff Girls didn't save Townsville. Just watch the episode 'Girls Gone Mild.' In it, two stuck-up parents ban the PPG from using their powers and everyone almost gets mauled by the Dooks of Doom. Sometimes violence is necessary, kiddies.
Sedusa. Yeah. She's a play on Medusa but you can still catch a few innuendos their and she wears spandex with fishnets and boots. Actually, the show does have quite a few innuendos. Such as HIM being a cross-dressing demon. But that's kind of funny. And if you are worried about scare factor, what kid will be scared of a cross-dressing demon? Aren't all the liberals encouraging the gays anyways... Back to my point, most of the innuendos in the Powerpuff Girls will not be caught by a kid. Or they shouldn't be. Bad parents.
Mojo Jojo says curses a lot. He's kind of a role model in a way, because 'curses' is a lot better than the alternative. One episode of the PPG insinuates quite a few nasty words, but it is all bleeped out. The episode is actually called 'Curses.' Funny, right? If this worries you, just opt your kid out of the episode.
One episode. In the episode 'Collect Her' Lenny has every PPG merchandise available. It's for satire purposes though, and the episode is hilarious. But if 'consumerism' isn't for your little munchkin, don't watch this episode.
In summary, let your child watch the Powerpuff Girls. Don't deprive them of something great.