Tenant lost keys - wants lock replaced

[Jennifer Ndunda]

I have a tenant in northern VA that lost keys to the apartment. I came by and gave her copies of the keys and did not charge her for it. She is now asking for the locks to be changed as a result of her losing the keys. Who is responsible for paying for the change in locks? If the tenant is responsible can I deduct this from her security deposit or add it to rent? Thanks!