You can top her , its important to understand tho that when dealing with autos it has to be done early in order to give time to heal and continue growing because of the rate of growth of an auto . With that being said you always wanna make sure that the isnt showing any signs of preflower anything like that because you dont wanna stress her out and then stunt her in growth . To me topping is only really a method of training your plant to grow wider , just because you top your plant doesn't always mean more yield . I did a test on a diary to see and the plant that I didn't top actually yielded more then the plants I had topped . So to answer your question topping is really a preference thing , some people will swear by it and some people won't at the end of the day the choice is yours :) I hope this information helps shed some light into your grow :D -Happy Growing!