Hey Becky, I just peaked at your SS and it is interesting. Bubba has a late nadir and his SS looked a bit like yours. He doesn't always have a late nadir so it made figuring out his patterns hard. It's hard to know right now if kitty (sorry don't know your kitty's name ) is hanging onto the insulin more than 12 hours thus the lower green numbers or if kitty is nadiring then.
Can you some test in at night which will really help us to see the patterns a bit better also most cats go lower during the night time. And another good time would be to get a +11 in the PM cycle so we can see if kitty is still dropping or on the way back up again. The more varied times of test you can get will help to figure it out.