The only reason that it being only just banned as of 1 January is if the last time she took the drug was in December. Technically, in that case she would not have violated the rules. But her confession pretty much sounds like she did take the drug in January, so she violated the rules and that's all there is to it.
There's really no excuse for her and her management team and her medical team to all plead ignorance of the change to the banned list. I bet her doctor and coach knew very well that a lot of athletes were using it as a performance enhancer, and that it would probably one day appear on the banned list. I would have expected they would scrutinise the banned list every year to see if it finally made it on the list and in each previous year they would have said "all right, one more year!"
As I said, I think he doctor or coach or manager knew this was now banned, but they decided to let her take it for the Aussie open in the hopes that she wouldn't be pinged for it, and after the Aussie open they would stop her from using it. If she can prove ignorance and also show that someone in her team knew about it and let her keep taking it I reckon she could sue her management team.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."