Road Bike Question

My girlfriend has an extremely entry level road bike right now and has figured out she likes biking and is going to continue riding. We are signed up for the STP(Seattle to Portland) this summer. All her riding is going to be almost all training rides. We did 27 miles this last weekend and it is only going to go up from there. We will be riding every weekend for the most part. She is looking to spend between 1000-1400 bucks. We have found your typical aluminum bikes with 105 for as low as 1000, one Fuji Aluminum bike with Sram Rival(I would consider a slight upgrade from 105) for $1100, an aluminum bike with Ultegra for 1300 and a full carbon bike with 105 for $1400.

The basic question would be seeing how she is going to use the bike would you rather have an aluminum bike with ultegra or 105(cheaper) or a carbon bike with 105? I am leaning towards the Carbon bike because of the better ride and less wear and tear and the body. I don't think the better components will benefit her as much as the carbon frame. Thoughts?