First Outdoor Grow Question

I started some plants for a friend of mine. We put them in the ground about 3 weeks ago and they have already started showing the sex. Is this normal?

yes normally between weeks 3-4 of veg they will show signs of what sex they are

I know that when I do my indoor grow. I start flower at 4 weeks old. That's from seed to flowering. Once I stat flower them they go about 10 weeks and there done. I thought. That they start showing their sex a few weeks into flowering? If that's true then these plant would have about 8-10weeks till there done? That being said this would mean that these woul d be done in end of July to mid aug, but most people say that outdoor grows don't finish till October. ????

yah mine started showing sex way before it started flowering for some unknown reason but dont worry its completly normal