Firstly, glandular fever is not very contagious. It is passed by close contact between individuals (via saliva), and even members of the same family do not necessarily catch it from each other. The incubation period (time from infection until appearance of symptoms) is between four and six weeks. Individuals with glandular fever are usually infectious for a period of weeks.
However, the Epstein Barr virus that is responsible for glandular fever may be shed intermittently by people who have previously been infected by it, and is often present in the saliva of seemingly healthy individuals. For this reason it is impossible to eradicate the infection. Once an individual has had the infection, they will be immune to it in the future. You may well be immune and your immunity will also protect your child in the early weeks and longer if you breastfeed.
Young children and babies are rarely affected by glandular fever, unlike older children and adults who tend to develop fever, fatigue, inflamed tonsils and throat, and enlarged lymph nodes.