I don't want to get too disruptive when this seems to be working for your partner but there's quite a few things in your post that set off my alarm bells about storing problems up for the future.
Firstly, there is no such thing as 'natural' sugar. All sugar is natural. Even the white stuff in packets came from sugar beets originally.
Secondly, your body doesn't differentiate between sugar sources. 10g of sugar as granules is the same as 10 grams of sugar in honey. It's all just sugar. So don't fall into the trap of thinking fruit sugar is good and sugar in chocolate is bad - it's all sugar and can all be bad. Fruit sugars can actually be even worse because fructose has to be converted to fat first before it can be metabolised for energy.
Thirdly, I'm a little worried about the snacking. If your partner is on multiple injections, there's no need to snack and she shouldn't be going low between meals. No-one on multiple injections should ever have to specifically plan in carby snacks to prevent their blood sugar from going low - they should be taking less insulin with their meals or reducing your basal insulin. Snacking to keep your blood sugar up the whole time is just 'feeding the insulin' and is a sure-fire way to gain weight quickly and increase insulin resistance. Her blood sugars may be good but do remember that all glucose in the blood that isn't used for energy is turned into fat by insulin.
This is one of the hardest lessons to learn about diabetes - some of the habits that work effectively for blood sugar management can actually cause some quite major issues in the long-term. I think what you've achieved together is incredible - and with a few minor tweaks, it'll be perfection. Good luck!