Frustrated mom -
first of all a big hug! <hugs> I'm fairly new here too having just found these boards this spring but you've definitely landed in a good place for support!
One question I have is what type of Ritalin is she on? Long acting? Or does she take the generic every 4 hours? Does she take a step down dose in the afternoon? I know for mine, he was rebounding really hard after his long acting wore off mid-afternoon and he was a horrific bear until we got him on a step down dose to help him in the afternoons and evenings.
The other question I have is whether or not you've had a sensory processing/sensory integration evaluation completed for your daughter by an Occupational Therapist? Many children who are diagnosed AD/HD also have sensory issues which can overload them at school. By the time they get home, the child can't tolerate much at all and everything can seem to set him/her off.
Finally, have you tried any positive reinforcement systems? Punishment (aka negative reinforcements) only stop the immediate behavior and can often lead to lying, stealing, cheating - there's usually limited or minimal carryover of learning from having something taken away. Positive reinforcement, done unexpectedly, e.g. praising immediately when you see the behavior you want tends to have a more beneficial effect in the long run. My son does great on a token economy system, he's been diagnosed with AD/HD and ODD, but it can be a lot of work and requires that I'm on top of the ball and very structured and very consistent for it to work. Thankfully I've been able to be so and it's been a big turn around for him behavior wise.