As I mentioned before, my Verizon iPhone 5 did not come with a sim card and I did not buy a sim card. So unless Verizon placed the sim inside my iPhone 5...mine does not have a sim and works perfectly fine. Even connects to LTE. Also, my sis got her iPhone 5 at the Verizon store and I didn't see the rep placing a sim in the phone and hers work just fine.
Yes, because iPhone 5s come with SIM cards already in the phone. This is the same with all iPhones that use SIM cards - they already are in the phone. Apple has never produced an iPhone where they give you a separate SIM card and you need to use a paper clip to eject the tray and insert it. It's never been like that - when carriers activate, they activate the SIM inside the phone.
If your sister wants to try an experiment, use a paper clip to eject the SIM in her new iPhone 5. It will be a Verizon SIM, and if she doesn't put it back in, it will not connect to the service.
If your iPhone did not come with one, you need to visit a Verizon Wireless corporate store or call 1-800-922-0204 to request a new one. It is free and they can have it shipped it to you ASAP.