The short answer
No vaccinations are legally required to enter Morocco from most countries, for adults or children. Check with your GP or a travel clinic four to six weeks before you go. Hepatitis A, typhoid and tetanus boosters are commonly advised, and malaria risk is negligible. Make sure routine childhood vaccinations are up to date.
In more detail
Entry rules are simple for most nationalities: no vaccination certificate is needed. Health advice is a separate question, and it depends on your child's age, health and plans, which is why a GP or travel clinic visit a month or more ahead is the sensible first step.
Commonly advised boosters for Morocco include hepatitis A, typhoid and tetanus. Rabies pre-exposure is worth considering for long rural stays. Malaria risk in Morocco is negligible and prophylaxis is not typically recommended. For children, the clinic will also check routine vaccinations.
Day to day, most health issues for children in Marrakech are stomach upsets and too much sun. Bottled water, food cooked hot, high-factor sun cream and rehydration sachets cover most of it. Pharmacies are well stocked in Gueliz and around the medina, and the city has private clinics.
Keep the animals at a distance. The snake charmers and the Barbary macaques on Jemaa el-Fnaa are best watched from a few metres away,. Comprehensive travel insurance with medical cover is worth having for every family member.