C.M.
I'd say your only issue is you're not committing to the course until you see it through to the end.
If you just put her back in bed without saying anything, you have to KEEP DOING IT until she gives up. Basically you are pitting your will against her's so you have to keep doing it until she realizes that she's not going to win. That might mean 10 times, it might mean ALL NIGHT. Do know that it will get easier, but you have to COMMIT to it, and know that there will be a few nights where it takes hours and hours for her to go down. You just can't give up and you certainly can't lose your temper over it.
You read for only 30 minutes? That's not long enough, not in the beginning. Maybe after she gets in the groove of things.
You're going to have to commit to a course and then stick with it for a LONG time. There are many options beyond what Supernanny suggests, but if you don't commit to the FULL COURSE of any of them, then nothing will work.
Good luck!