Thank you for writing to JustAsk. Before you can establish a tutorial program you need to see what programs for behavior have been outlined by the school district. If your cousin has not been receiving any behavioral interventions then his/her parent or guardian should ask for a meeting with professionals within the school that help to evaluate and determine programming, if needed, for children with special learning challenges.
In the meantime, without knowing the kinds of assistance he/she needs, I would recommend trips to library for her to peruse all kinds of books, computer programs and fun resources. (Some even have educational games you can borrow for a short while.) The children's librarian can assist you. Also, many school districts have family support centers that provide materials for summer development.
There are several great links on this website full of fun ideas that help with learning for entering second graders.
You may also find the website below fun for a child with attending and learning challenges.