I'd be feeding hay in the morning too, unless she doesn't finish her night time meal long before the arvo feed. If the horse is not too fat, I generally like to opt for free choice hay/grazing.
I would definitely change the molichaff for unsweetened. It's not just her feet it's bad for, but feeding regular junk food, as is the case with people, can cause metabolic problems & it is this that can cause laminitis. Sugary, starchy feeds can potentially cause ulcers & hind gut acidosis, which can also lead to lami. So as with kids & lollies, small amounts occasionally aren't generally a problem, but feeding them as regular meals aren't so good.
Don't know what 'cool mix' you're feeding, whether that's also a high starch/grain based feed, whether it comes under the same sort of banner as above, but while it's important to feed all feeds to horses little & often, it's particularly important with starchy feeds, to minimise risks such as the above. So I'd be feeding those type ingredients in at least 3-4 small feeds daily, or if that's not possible, keep to the low starch, high fibre 'health foods'.
Not currently in ridden work due to lack of saddle but is trotted up in hand daily and lunged twice a week for twenty minutes of walk, trot, canter transitions. Also ten minutes of join up prior to lunging.
Curious about this, as people have different ideas/approaches - she's 'trotted up' for 20 mins daily - do you run backwards & forwards with her, lead her from a car...? What does 10 mins join up mean? Is that 10 mins of fast circles, 10 mins moseying around, 10 mins of hanging out with her in a round pen? Why is she lunged for 20 mins twice a week?
and a couple of carrots (weaning her off these as she gets far too excited at the sight of them!) whilst brushing her down.
Instead of weaning her off them because she loves them, you could always use them to train her to be better mannered about them, or some such.
Also, when I start to bring her back into work (January) what changes should I make?
Depends what work. Generally if a horse is healthy & not in hard physical work, they shouldn't need extra calories for the usual kind of pleasure riding. You don't need to get complex about diets most of the time. generally IMO. A healthy horse shouldn't usually need any more than hay/grass and a good nutritional supplement. If/when problems begin to arise with that diet - the horse is losing too much weight or such - then you can add other ingredients. I find feedxl.com to be a great service/program for heling work out what's required & when, including specific considerations for specific horses & diseases.