You are lucky she told you. At least you can make your own mind up about the risk. Condoms work but are not 100% effective since it is a skin disease. Medication adds to the reduction of risk. Its up to you....
Good news! You CAN be in a relationship, fall in love with, even marry and have a baby with a woman who has herpes! It's amazing, isn't it? Unfortunately some folks on here make it sound like the plague, when it's not. Granted, it sounds like you've just met this girl, but a relationship has to start somewhere. Becoming educated is key in managing herpes in a relationship.
Here are odds based on female to male transmission of genital herpes. As you can see, the odds are very low. You should be tested as well, as most folks don't even know they have herpes.
FEMALE TO MALE RATE OF TRANSMISSION (HSV2 ONLY STATS IS NOT APPLICABLE FOR HSV1)
If you have 100 couples where the female has HSV2 but not the male (these figures are over a year) the odds of female to male transmission are, if you do nothing other than avoid sex during an outbreak, 4 men out of a 100 will get herpes in a year, or 4%. If you do go on a suppressive therapy then it drops to 2 men out of a 100 in a year, or 2%. And if you use suppressive and a condom the chances are 1 man out of a 100 will get herpes in one year or 1%.
The Valtrex and transmission study stats are based on having sex 2 times/week.
Become educated even further by reading the Herpes Handbook here:
If you find that the free handbook isn't enough info, check out Terri Warren's new book - "The Good News About the Bad News" - it goes into far more detail and is very helpful for newly diagnosed people and their partners.