You can try to scare her into the $500 with threat of small claims court but it's probably not worth the hassle of going through that process. 

A move-in ready home under $400k is a very quickly vanishing product.Why is this still happening, despite significantly higher prices and the looming threat of inflation and interest rate hikes?

No mention of disturbing the peace, just no [threats of] violence, btw..."2.Not only were landlord’s actions of lockout not allowed by statute, but case law also prohibited the action.

Some of the best advice I've received on this threat.  

@Tina LeeEngineering, IT, cyber security, nursing.

On the other hand, I get threats of legal action every few months.  

During the January 14, 1924 meeting, the open market committee notes: “While the situation clearly contains a threat of inflation, the time has not yet come to sell securities… We should continue to acquire more as far as we can do so…”.

If the tenant is threating damage to the house in response to an eviction, then I would have seller contact police, additionally, the law provides for landlords to access their property with proper notice and refusal by the tenant is a violation of the law, the seler could have the police come to witness the access and eliminate any danger to the seller.

CAA also keeps you in the loop on upcoming laws, threats, etc.Best of luck!

The latter is something that doesn't get resolved by reasoning or even threat.