I just now that legally it is allowed in Islam according to the Shariha law.. Our prophet Mohammed (peace be upon him) married Ayesha when he was in his fifties and she was just 9 BUT she did not come to stay with him till she reached puberty at the age of 12 or something..
In Islam, muslim men are told to marry of their daughters as soon as they reach puberty so that they don't go around experimenting..