Complex sentence: She gained notoriety for being the girlfriend of Manchester United star Cristiano Ronaldo, 9 years younger, which made her the target of several Cristiano fans who started Anti-Merche sites.
Split into simpler sentences: She gained notoriety for being the girlfriend of Manchester United star Cristiano Ronaldo, 9 years her junior. Which made her the target of several Cristiano fans who started Anti-Merche sites.