Good on you for calling the cops. Serve management with written notice, too (keep a copy of this!), informing them that if they don't do anything about her, and she damages any of your own property, or harms either of you, that you'll be going after the management company. Might want to also tell you that you'll break the lease then, too.
Expect flak from them, but your personal safety is more important than your lease.