Mindy,
I think your plan sounds like a good one! I agree that it's would work well to just slow CTC down and work on the skills in the guide until your daughter gains some confidence and some practice in those areas. You will actually still be making good progress skill-wise, and the training will really help her in the days to come!
I do think that shifting from Shurley English to Rod and Staff will save you precious teaching time. As 8arrows mentioned, Shurley is a good, solid English program. However, I agree that it is very time-intensive for the teacher. My older sister uses it with her kiddos but has really pared down the lessons and skips levels of Shurley, stretching one level out over two years (and this from a high school grammar teacher by profession)!
So, in your switch to Rod and Staff make sure to get the right level, so it isn't too hard. Also, make sure to do MUCH of the lesson orally or on a white board, only assigning one portion to be done on paper each day. This will really keep your time down and will still make sure your daughter gets the solid grammar content that is needed. Also, be sure to do the 5 question oral review at the beginning of each Rod and Staff lesson each day.
In all honesty, it's so important skill-wise for kiddos to have solid reading and writing instruction as they head into middle school (in preparation for high school). So, if you are able to shift DITHR and Write with the Best back into your schedule (doing DITHR 3 days a week and Write with the Best 2 days a week as scheduled in CTC) that would be great. Go ahead and slow down the rest of CTC, but try to keep those areas on track if at all possible. Strong language arts and math skills are right behind time spent in God's word as far as importance for the future goes.
Blessings,
Carrie