Very interesting, Michele.
I think 1u is not enough to hold her unless he is coming off a really low day. It does not look like she drop too low last night and the 255 this am was rebound. I think it was not enough insulin overnight. But clearly 2u is too much - or seems to be. You don't know is she was as low as the 30s or just the 50s today.
So, you need to figure out a new "sliding scale" Maybe 1u or 1.25u when she is in low-mid 100s and 1.5u above, hmmm, maybe 175? Maybe 200? What do you think?
For night I would say 1u, but if she goes higher again tomorrow am, don't give another 2u. Probably 1.5u this am would have been good.