Hi Rosie,
Do you have anymore information about the girl? The anemia, low immune system and enlarged spleen could all be related to thalassemia but it could also be something else. If your friend is a resident of the same country you live in, then it's most likely the baby was not tested at birth for hemoglobin disorders, because it isn't mandatory. If it is a possibility at all, a hemoglobin electrophoresis test should be done to check for thal. This is a simple blood test. If you have anymore information about tests she has had, such as a complete blood count, that may also give some clues. I would not rule out the possibility of thal or another blood disorder without having more information. Genetic background can also be of some help. Much of the thalassemia in your area is Mediterranean in origin. If this is suspected to be thalassemia, I can put you in touch with a local association that will direct you to a thal specialist.