Yesterday a new trainee started at our company (software developer). She is a trainee ("Auszubildende") under the German apprenticeship system, and thus covered by special rules and regulations. Because her instructor is still on vacation I was told to look after her and help her with her first tasks.
She told me she was allowed to leave early on Friday to visit someone, if she stays longer the first two days.
Seemed fine with me.
This morning I asked her what she accomplished when I was gone yesterday and she told me she stayed till 7PM. I was a little shocked because her work seemed rushed and not really satisfactory. I helped her a little and went for a smoke break with other colleagues. I asked them for advice how to help her with her start, because she stayed so long, and I didn't want her to get demotivated.
One of them told me: "Long? she left at 5:30!"*
Which is only 15 minutes after me.
Problem: I don't care that she left at 5:30, starting at 8 with a 1h break she stayed longer than she had to. I care about that she lied to me on her first day. For no apparent reason.
Question: How should I explain to her, that being honest is very important when working with us? I don't want to run over and tell her "I know you lied to me Bob saw you leave!" I also want to protect her from what would have happenend if her actual instructor would have seen that. Since she is still in her probabtion period, it might have been enough to let her go.
She is still very young and naive, and probably didn't have bad intentions.
Additional Information: She is over the age of 18 and a legal adult, she did finish school (Realschule), she did a small internship before, so it is only her first day of her apprenticeship, not her first day over all. She is allowed to work up to 10h a day, but only 40h a week. We don't have time keeping, we just trust each other. She can start between 7AM and 10AM and leave basically when she wants to, as long as she is doing 40h a week.
UPDATE: I did exactly what Joe recommended: She told me she must have misread the clock, and told me she called someone when she went to the trains station. Looked up the time in her phone and said: "Oh 17:36, I must have misread the time". I hope she won't be this sloppy again. I am not sure I believe her entirely, but it doesn't matter, she came clean the moment she had the chance to.
* He is sure, I asked him if he saw her pack her laptop, and he told me that she packed everything and asked Bob2 if she could leave, and he said yes.