OCD sufferer here, if possible to address each point below 1-by-1 it will mean less annoying follow-up on my end :)

1.  Why would you assume that this is her first outbreak?  had she very recently received oral sex from someone else?  That's the only way really that this would be a first outbreak  If it is her first outbreak/new infection, she will be shedding virus on about 13% of days for a few months and there is a real risk of acquiring this from her during intercourse.  Condoms reduce transmission from women to men for HSV 2 by about 65% and I would think if this is truly a brand new infection for her, the percentage of protection for you would be similar---

Huh, just a little confused. Previous posts on this forum seemed to suggest genital to genital HSV1 transmission is very rare, like VERY rare? Whereas yes I know that passing oral HSV1 to someone's genitals is quite common with or without active cold sores.

Yes, genital to genital transmission is rare, but people with a brand new infection shed virus a lot more than people who have been infected for a while.  I formulated my answer to your question based on you saying you think she has brand new infection.  People with established HSV 2 infection shed virus anywhere from 10-20% of days on average, depending upon whether they have symptoms or not.  People with brand new HSV 1 genital infection shed virus somewhere in that same frequency.  ---

Got it! I think she assumed this was a new infection since she had never experienced something similar before, and I thought with genital hsv1 often the pattern is a bad first outbreak and then maybe milder or no outbreaks in the future. 

Exactly.  If we knew this was a recurrence, I would say the risk of acquiring this from her would be very very low indeed!---