Yes. So, what is the problem? or is there one? (why not just do exactly what you said).
I mean, if the jpegs aren't imported yet, then you'll need to import them.
I guess I don't understand the issue or reason for the question - you can edit/export either raws or jpegs - your choice - I don't see where the "complexity" is..
Okay, I probably didn't explain this well enough. Both JPEGs and RAWs are imported by Lightroom by default, right? After I have developed some of the RAWs I'd like to export both developed RAWs and the camera processed JPEGs (that I can't see since they are sideloaded(?)) to new folder. So essentially I would like lightroom to export the processed RAWs as JPEGs to a new folder and copy the camera processed JPEGs into the same folder. I can export the pictures the same folder they are already in, but then I have to overwrite the original JPEGs. Is this any clearer?
I can't see since they are sideloaded
Ah - I should have thought of that.
If your jpegs are being considered "sidecars" to the raws, then technically, they have not been imported. ("sidecar" means "not imported" but aware of it's existence, in case of move or rename..).
So, you need to:
* Change the Lr preference to have raws + jpegs treated separately.
To separate, consider using my (free) RawPlusJpeg plugin which has a feature especially for it.
I think you can also do it without the plugin, but I don't remember how - involves re-syncing the folder I think (after changing the Lr preference to treat separately).
note. raw and the jpg copies are not imported as default
Rob has give the right answer; however you could make a separate folder for the jpg files and then import. You will need to un-tick "don't import suspected duplicate" [right hand panel]
I have usually found when LR doesn't do as I want it's usually because I haven't done it right in the first place.