I think it all depends on how Maggie recovers from the anaesthetic really.
Take some of her usual dry food, and a small selection of her favourite vegetables (you don't need to take the whole veg drawer, just a few bits of some things that they could use to tempt her to eat with if necessary).
If she's anything like my Maggie, you won't even know she's had an anaesthetic - after being GA'd and the vet probing around in her throat, scooping bits out etc. the first thing she did was start eating!
On the way home, you'll need to keep her warm (it's pretty cold at the moment, but after a GA their temperature can drop), so maybe take a snugglesafe or similar and ask the vet to microwave it and pop it in her carrier for you.
When you get home, it's important to monitor input and output post op, as their digestive transit can slow down - my Maggie has bloat after each GA (last time, I literally went from the specialist in Swindon, straight to my local vet, it developed quickly halfway home. Talking to your vet about gastroprokinetics may be a good idea - some vets will give a jab of these as routine after a GA, others don't. (Also discuss pain relief, antibiotics, probiotics and vitamin C.) I separate mine for at least 24 hours post GA, so I can see what the pig in question is eating, and what they're producing urine/faeces wise. I separate with a divider of C&C grids, so they can still see/talk to each other.
Have a look at her wound(s) when she gets home. Take a photo if necessary, so that you know what it looks like. This way you will be able to tell if it's getting swollen or inflamed or anything.
