Why did God choose a little girl, a child to impregnate? Isn't that a terrible thing to happen to a child?

Dear beautiful sister , you under estimate GOD POWER , GOD is the MOST KNOWLEDGEABLE ,HE know everything in advance , God do everything whenever HE WANT , do you have the exact date of that event ?Even if she was 13 yrs old ,where is your Problem ?I accept what ever GOD do , i have no complaint