@Monkey D. Goku It's hard to tell this early. A rough guess might be that she thought he was safer without her. As a powerful potential contender who didn't want to be involved taking his side would have dragged her into the middle of it and potentially placed him in more danger. Merciless bullying aside, being weak and easily overlooked isn't exactly the worst position to be in during a blo*** family feud. The worst would be having enough power and influence to be seen as a threat but not enough to protect yourself. Having her as a sole protector would have elevated him from the first to the second.