Good morning!
That 51 is at the end of the cycle. When she wasn't bouncing, her pattern seems to be that the AMPS was about the same as her late cycle number.
If so, that's fine, although you may need a dose reduction. If she's still about the same at PS, feed and wait 1/2 an hour, and test again.
Did you give low carb food? That's good. You want to stop her from dropping anymore, but not lose ground. (If she does drop more - like into the 40s/30s, then give a very small amount of high carb and/or rub some karo syrup on her gums.
Test again, maybe even twice (sorry Callie!) before the PS to make sure she isn't still dropping. Put each number in your subject line of this post as you get it, because we definitely want lots of eyes on Callie today. Also put the question mark and maybe that green face with the teeth in your subject line, and dosing advice too.
Lantus land has a whole system of when and how to go about the dose decreases. Tritone was such a difficult, weird case - I don't have experience weaning a perfectly normal cat off insulin...