It's the other way around actually. Enzo (Valentina's father) doesn't let Valentina and any other rider in their team to compete for Italy at championships...
Italian federation got angry at Enzo for selling Eremo del Castegno (Valentina's top horse) right before Rio, even though the federation was paying them to keep the horse until Rio 2016. Enzo however claimed that they didn't break the deal because they still qualified for Rio on Eremo (and eventually competed with experienced Chablis)...
Italian federation in fact sued Enzo, but apparently in the end the lawsuit was dropped and settlement outside court was made.