Is it a good idea to get a small pressure cooker to cook meals for my 13 months old boy ? Like porridge , soup etc.. heard is time saving and retains nutrition better

yes u can. but u might also want to consider what u want to feed him in the long term - e.g. if he is going to be eating the same stuff as the family. i don't have one as we just cook small portions or freeze the extras or the rest of the family eats the same