Good luck to the both of you!
The training is most of the fun. That's great that you have watched her grow throughout the process of getting to your first tri.
3 years ago, I use to take my boyfriend running. He would slog along and barely keep up, huffing and puffing like he was about to die. Then 2 weeks ago he completed a 9 mile run with a 9 minute mile. Along with that... he taught himself to swim to compete in tri's and he use to barely ride 10 miles and now he can ride 65 miles with a 17 mph average. So... I understand getting the joy of watching someone grow into being an athlete.
Have a great race and feel free to come back with a race report.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"