I get where her mom is coming from. Black people, and black women in particular, rightly have concerns about retaliation when it comes engaging management at a workplace, either from the culprits who tend to be entitled or by management itself that doesn't generally value the individual concerns over the perception of liability. Also, while Vamped didn't indicate ethnicity, there's a good chance that the security guards are also black and any action by a majority white upper management and minority workers is going to exacerbate the situation. This isn't to say that she should be confronting anyone directly, just to point out that Vamped is being put in an extremely bad position through no fault of her own.
Nonetheless, she absolutely did the right thing. Having management deal with the issue is the only possible option, as bad an option as it is. A confrontation as her mom suggested would be even worse. These guys are entitled enough to sexual harass her openly, so they could be extremely dangerous to approach.