BAD WORK SITUATION WHAT SHOULD SHE DO

Say somone at work happened to steal something from work. And it’s their first job ever. Then people find out and investigate who did it. What should that person do? They really cannot be fired but they feel very guilty and have remorse. Should they keep working while it’s under “investigation” and once they confront you, say sorry and cry and own up to it. Or immediately quit so they don’t get fired and it put on their record. Or keep working and when they confront you be confused and say they’re a kleptic and can’t help it. Or what?? I get what she did was wrong but I’m her friend and I don’t want her to be in huge trouble and permanently put on her thing and won’t be able to go to college or get another job ever. What should she do?