I've not used the SLGS method, but it looks like you try going without insulin if kitty earns a reduction from the .25 unit dose. After that, she is considered in remission if she goes 14 days without needing insulin. Here is the bit from the document on the SLGS method.
Remission:
Remission is reached when kitty can go 14 days without insulin while maintaining normal blood glucose values in the 50 - 120 mg/dL (2.7 - 6.6 mmol/L) range. Most will remain in the 50 - 80mg/dL (2.7 - 4.4 mmol/L) range. However, some will experience infrequent BG numbers higher than the norm. Continue feeding low carb food. Test the cat's BGs once per month. If BG numbers begin to trend upwards, it's time to bring kitty in to see your vet for a check-up. Common reasons for kitty falling out of remission include dental issues, infection, inflammation, pancreatitis, etc. Just about any illness or disease can do it.