Absolutely go for the smaller group if those are the two choices. I personally prefer private lessons, but if that's not an option, the smaller group will allow her to receive more attention than the regular group lesson. A small group lesson may even give her the opportunity to learn from other people's successes and/or mistakes. I like the one-day vs. two days of lessons, too, because I'm someone that needs time on my own to process everything and practice what I've learned before I get more instruction. Have a great time!