My two boys were neutered last week, they both are about two year old, well one was 2 in January (Peter), the other I rescued in Jan 2019 his age is unknown so at least two years or older (Fred).
I've got small cages for them like 80x50cm and standard 50 cm high so they only have one level and there's no much room for stretching so they get plenty of their fav hay and their usual food and water and some extra greens so mainly relaxing and have some extra chewing toys as well to keep them busy. They're getting some extra carrot as well. Also important that they start eating as soon as possible so their gut won't stop moving.
Fred is doing very well and he acts like he never had them at all, but Peter was very upset and was trying to fix it so we needed some extra care. But now he's fine I didn't put any collar on him it is healing now and he is eating well again and almost like his old self again. Fred is healing really quickly all looking healthy, this is day 6 and hope they will heal soon.
Hopefully your bun won't be interested in stitches but be prepared. Some people use e-collar after surgery but they won't be able to reach their cecotropes with it so I would say it's only if she really needs it. With Peter I thought about e-collar but we just spent lots of time together he loves being held and is very relaxed and just stays on my chest can stay for hours, and after that he is usually so happy and relaxed so he is usually just sleeping after so I used that and no collar just holding him on me for hours.