Photoshop Elements has been able to open Jpegs in Camera Raw for quite a few versions now (since V6, maybe?). It's very easy to do, as I'll show you.
First, let me reiterate - I can take my cat to a zoo, but that doesn't make it a tiger! Likewise, you can open Jpegs in a Raw program, but that doesn't make them Raw files! Editing a Jpeg in ACR is fun, but it's still a Jpeg. If you want real control and flexibility when editing, shoot Raw. [/rant]
First, go to File>Open As:
At the bottom, change the format to "Camera Raw":
Choose your image, and press "Open":
Voila! There it is in ACR:
Do your editing, then press "Open Image" to bring it into Elements for further work.