You know your daughter best, so if you think she can handle the responsibility, then I say go for it! If you get the puppy for her, then she can use her money to buy it the things it needs.
I got Mr. Biggs my 3rd year in college. I went to school full time and had just stated working. My mother was totally against me getting a dog, but if I had listed to her, then we wouldn't have Mr. biggs. Having him made me even more responsible in that I picked up more hours to make more money for the things he needed and to buy him tons of clothes. lol.
Oh, and he definately made me a lot less lonely and a lot less homesick. lol
