I have not done this particular event, but all of the OBRA events I have been to have been very well run. (did I mention that the husband of one of my team mates is the OBRA executive director ) If she (or you) wants to be in contention for a medal she will have to buy a $20 annual license in addition to the entry fee. If she (or you) doesn't care it will only cost you $5 extra for a single day license.

I will tell you as triathletes you may stand a good chance of medaling, especially if you register as a 4... you will both be classified as either cat 4's (since you haven't road raced you can't be classified higher, even though from triathlons you are strong) or if you are old enough and you can choose masters, though it does appear to be open master's categories, so you could be competing against women of any category who are in that age bracket.