When quantifying repetition I'm only going to count it if the first thing the grandmother says is the exact same as Evie, it still counts if she adds something on the end.
Quantified data:

I expected to find more CDS in the 'all the things' transcript as it was 4 minutes and 33 seconds long while the 'castle' transcript was 3 minutes long. This pattern was found in the quantified tag questions and the repairs but there was 3 more repetitions in the 'castle' transcript. 
Analysis:
In both transcripts Evie's grandmother uses multiple tag questions to keep the conversations moving along. A common theme in both of the transcripts is that the grandmother likes to use very general questions such as "what else shall we do" in the 'all the things' transcript and "now what are you going to do" in the castle transcript. The grandmother also uses tag questions that are more typical to the conversation but repeats them multiple times. In the 'all the things' transcript she asks who else they should take a picture of 3 times in the transcript, and in the 'castle' transcript the grandmother asks who's going in the castle 3 times. By doing this it allows the grandmother to be not too intrusive into Evie's conversation and allows her to be more imaginative in her story. There is possible more tag questions in the 'all the thing' transcript as the story is more about Evie and her grandmother rather than just Evie as shown by the use of "you" in 'castle' and the inclusive "we" in 'all the things'. As the grandmother is using 'we' it shows that she recognises that she has an active role in the scenario as picture taker and so asks double the amount of tag questions. In the 'castle' transcript the grandmother could possibly want to get involved less and so would ask less tag questions.
The use of repetition forms a similar function to the tag questions. By repeating the same thing Evie says it shows that the grandmother is listening to her story and possibly helps Evie keep track of what she is talking about. There is possibly more repetition in the 'castle' transcript as Evie is 5 months younger in it so the grandmother would be using repetition as a form of positive reinforcement for her.
The 5 month age gap between the 2 transcripts could also be the reason behind why there is more repairs in the 'all the things' transcript. The grandmother could possibly feel that because Evie has a slightly stronger understanding of language that she doesn't need the positive reinforcement of repetition and that by modelling a standard it could help her learn easier, at Evie's age she probably wouldn't see repair as negative reinforcement and probably wouldn't recognise her grandmother is repairing her. The main use of repair in the 'all the tings' transcript is the repairing to the pronunciation of words, at first when Evie said 'picture' she said it more like 'pitter', however after her grandmother said it correctly Evie began to pronounce the 'c' more often. In the 'castle' transcript there is much less repairs with the main one being when the grandmother elaborates Evie's "sit sit sit" to "do you want grandma to sit there".