Whenever she has an active sore, she is shedding virus.
She should not be kissing people when these lesions are present.
yes, she is contagious.
While it is true that 60% of the general population is carrying this virus by the age of 20, it is still not something that should be spread around so carelessly. I'm sure you will not appreciate it if you get it and then have to live with recurrent sores the rest of your life.
No, the virus does NOT have to encounter broken skin in order to infect you -- contact with normal skin is all that is necessary. You may or may not have contracted it -- no need to panic, but all you can do is watch and wait to see if you get a skin sore. Hopefully not, if your contact was minimal and brief, but you just cannot tell.
I'm an infectious disease specialist - MD