Hi man very surprised nobody answered this yet. It could be down to a huge amount of things. I gather she's doing okay now ? for future reference it can be many things like I said. Ph imbalances can slow her down, overwatering can slow her down, change in temps can slow her down the list goes on and on. Sometimes its nothing to do with anything you have done sometimes its just the pheno growing slower. I have experienced this. This backs up the theory that all phenos are different regardless of breed. If you plant two seeds of the same strain from the same mother they will still be two completely different plants. though they will be similar they will have different characteristics and will grow with different traits. Slow growth can be one of these traits though breeders do their best to breed this out of the pheno. Either way shes healthy and patience is the name of this game. Unless you are perpetual grower im not seeing how it would be a problem for you :) Happy growing 👊