I wanted to write some ideas on what you can do if you realize that you're not going to make it through your curriculum. Just some suggestions.
1. Look through the curriculum, and find some parts you can skip. Does your student already know a part fairly well you can skip? Can you take some end of the chapter test and use that information to determined what parts you can skip? Did you cover another part last year that you can skip?
2. Continue the curriculum through the summer. We do math all year. It seems that stopping math doesn't help at our house. Sometimes doing something even 2-3 days per week in the summer will get you through.
3. Continue the curriculum through the next year. Sonlight cores can be done in 18 months.
4. Double up on some parts. For instance do two worksheets only doing every 2nd or 3rd problem on each one. This is a good thing to do if you want your student to not completely skip something and review a topic being covered. .
5. If it involves reading books, maybe get some on CD or downloads from the library for some of the books covered. Your student still gets the exposure, but it moves along faster. Maybe listen to them in the car or while you are at an appointment.
6. Can you substitute a one day field trip for a topic? Can you carry that topic to the next year?
I am sure there are many more ideas. You know your student best, and can determine what they need.