Kmart fired my friend?

Kmart has did rewards system. My firend is 19 years old and she was doing a great job in her kmart job. Unfortunately she was getting points from other customers and she used it for personal use. She did not knew the consequences.She wanted to tell the manager but it was too late. The loss prevention came up to her and said she used 50.00 dollars and she needs to come back to job and pay that full amount. They fired her for that. She is worried she does not know what to do she says it might affect her future employment with another company. The manager said it was not malicious but they fired her anyway. Could this affect her future employment with another company.