Is the issue a lack of Yiras HaShamayim? Someone who has a problem with stealing (for example, keeping silent when the grocery store clerk fails to charge you for an item), with swearing (after all, I was really angry, and the words just came out), or with lashon hara (I wasn’t the first to speak lashon hara at the Kiddush) has the same basic issue as someone with a problem with lying: they act as if there is no eye to see or ear to hear what goes on.
It is hard to face the problem you have to struggle with day-to-day. It is much easier to see that something that is not a challenge for yourself can be a real problem for other people. This can then lead you to reflect that if you don’t have a problem with stealing because you know that the Abishter is watching, then you should apply the same insight to the thing you need to work on.
Perhaps the girl will respond if she sees that she has the strength to resist challenges that others have.