I also suggest Draconian from a music perspective, but it is mostly male vocals. Are you looking for female vocals like Jonas' in a metal band, or just female fronted bands you might like if you also like Katatonia?
Since it sounds like you DONT want operatic vocals. Unfortunately female fronted metal is rare, and when it exists it either sucks because the girl can't sing, or it is epic/folk. Lacuna Coil is big because they are one of the only metal bands with a good chick vocalist who do mainstream metal. I've also discovered a lot of nu/core chick metal coming out that is autotuned or screamy. We can thank Kesha and BrokenCyde for that.
Paramore
I don't like this band's earlier material and I hate Twilight, but this song sounds dangerously close to Katatonia (riff at the end is also ISISesque), and she has a good voice.
Battle of Mice
Features Julie Xmas, members of Neurosis
Made Out of Babies
The vocal style here is NOT like Jonas, let me just warn you...
Octavia Sperati
I don't think her voice is that great personally
Madder Mortem
Kidney Thieves
Now defunct but the albums out there are good
Otep
Sirenia
Love this band
Other bands with female vocals that you might like ranging from depressive to metal *Since everyone's opinion of 'gay' is entirely personal, forgive me if some of these are too fem)
Lycia
Slowdive
Cranes
Stoa
Tristania
Eluveitie
Unsun