I used to eat Weetabix a lot as a kid because it has specified, consistent carbs and it was at least repeatable without weighing it.
I've been on a long journey with nutrition and lifestyle, having had co-morbidities of Type 1 diabetes , and I now eat only real food and so virtually nothing with an ingredients list.
For my first meal of the day - call it breakfast - I usually have a large bowl of fruit chopped banana, apple/pear, mango/papaya, grapes, dares/figs, melon/cucumber with quite a bit of non-starchy vegetables (think salads) and I inject either all or part of my insulin dose an amount of time before eating to reduce the glucose spike which, tbf, would've occurred when eating Weetabix.
I might have chia seeds or walnuts but only a few for the omega 3 fats.
Hope your mother is doing well.
ATB
Mat
TLDR, sorry:
The drop in glucose level happens to me but in a manageable way. My injected insulin starts working, my food starts to be absorbed, my glucose level goes up and then back down, if I need to I top up with a fig or two or possibly top up the insulin. Insulin to carb ratio was 1unit to 10g but is now about 1unit to 15g+.
On not being hungry during the night there is a school of thought that says iften people may not be hungry because they lack nutrients but for other reasons such as thirst, boredom (hardly likely during sleep I guess), or craving carbs due to low blood glucose for example.
If your mother eats a few hours before bed without snacking after she may find she is fine with an empty stomach before bed and possibly sleeps better too.
Others say that eating protein makes them feel fuller for longer, and adding fibre may also have a similar effect while also allowing the microbes in the gut to feed in it and deliver energy back hours later.
Hope that helps
Mat