Does this area hurt?
I can't tell by the photos. Is this area an ulcer or is it a blister?
Yes but it is too blurry to see
Does your girlfriend have any open sores like this on her genitals?
Ok. This could either be skin irritation from inflammation or it could be a sexually transmitted disease such as syphyllis. The only way to tell is to go get tested by your doctor. In the meantime, you can apply some hydrocortisone cream to the area to see if this will make any inflammation go away. Hope this helps.