It depends really on the circumstances as to whether to tell her you love her or not. Does she act as though she may want more from you and the relationship or is she acting as if she is going with the flow? If the answer is yes to the first question and no to the second then I don't see where 6 months is too soon to tell her how you feel but the whole marriage and children thing may be a bit much and you do not want to scare her off. It also depends on your maturity as to whether or not it's normal to want so much all at once and after only 6 months. I would say yes to telling her your true feelings and no to telling her to what extent your feelings go, wait on telling her you want to marry her and have children with her and see how things go after you tell her your feelings and maybe ask her to move in a little while after telling her your feelings and depending on how she reacts to you revealing your feelings, after living together for a little while then you will know if the time is right for the rest of your plans with her. Don't come on too strong and possibly lose the best thing to happen to you.