Yes it's true , she is clearly the slowest of the batch but it could only be a bad start 🤞 it would be the best option in your case. If it is not a bad start It could also be related to the phenotype , maybe this gorilla glue is a weak phenotype compared to the others at the same age. Your environment is not the problem here as the other plants are thriving good , the best it to wait a bit more and see how she will evolve 😊👍