There are two strains of HSV. One most usually results in cold sores around the mouth or nose etc, the other more often results in them on the genitals. The former is very common and often caught in childhood, the latter is just common. One's treated as just one of those things, the other - thanks to marketing campaigns from pharmaceutical companies back in the 1970s - is 'OMG Herpes!' but they're very similar.
So it's probably the first she has. Have you ever had a cold sore yourself? If so, you already have the strain of HSV - you'll continue to get cold sores wherever that happens but almost certainly nowhere else. Your immune system can't get rid of the initial infection (the virus ends up hiding inside cells) but can stop other incidents before that happens.
If not, you might have caught it but you're more likely to get them around your mouth.