I think she left that key in her purse or her car, Maybe her camera bag. I could imagine her having to go to a job such as a wedding, or christening and it taking more time then a picture of a car. A whole evening or day possibly. So she may have kept that key in her purse. She could remove her camera and leave all her belongings, take that key and put it around her neck while shes off at a venue for an event she is take photographs for. Mean while all her other belongings in her car, purse, possibly her camera bag and her KEYS that she normally carries with her that would have her house, business, garage, and other car key on it are safe in her Locked car. They may be to bulky to carry around with her when she is working. The key around the neck on that lanyard would make sense to me. And it would make sense it be in her purse or left in her glove box.