Its the caffeine that she is most likely craving try bayer asprin and a coke its works best for me when I have that nagging headache.
She needs to see her dr. IT sounds like rebound headaches to me. I had them when I was on Excedrin. A good diet has never hurt anybody. Wish I could stick to one.
Oh, it seems I didn't read you post thoroughly sorry. I'd look at diet myself, maybe substitute the powders for some ibuprofen? Some form of herbal tea that is relaxing, maybe st johns wort. Honestly though I don't know. I'd think diet is the best way to treat something chronic but yea, hopefully someone here has a magic bullet for you.
I don't know if an addiction is the correct term here. I'd suggest possibly not. Aspirin, panadol/tylenol/acetaminophen, and caffeine would not generally fall under this category. Well, caffeine I guess, but I doubt that's the issue here to be honest.
Taking too much panadol though is very dangerous and can cause liver damage or death, which I'm assuming is what you are concerned about? This sounds more like a knowledge issue than an addiction issue, and she is simply unaware of the dangers of taking too much panadol. You need to educate her on the topic and/or find something for her headaches that doesn't contain panadol. Have a look at her diet too maybe, hopefully some people here can chime in with helpful tips for heachaces also.