What do you need in a midwifery bag?

My daughter is a student midwife starting her placements in January. I want to fill a bag with what she’ll need to survive home births and call for her birthday. I’m a family physician who did deliveries for 28 years so I know some of what she needs but I’d appreciate knowing what’s in your to go bag. What are your favourite sustaining treats when you are on call? Is a back pack better or a satchel (old style doctor bag)? What can’t you live without?