A couple of extra thoughts:
If you are using off camera lights, try to get them up higher. Your lighting is a bit flat. Try putting the key light on the side with the part so hair over the face does not cast shadow on the face.
Try moving your subjects further from the background. Frequently that will help with shadows on the background. They will be lower and softer.
Think about getting lens hoods for your zoom lenses. The 50 mm has a deeply recessed front element. The zoom lenses don’t. A hood improves contrast. You can purchase Canon hoods, or rubber ones that screw into the filter threads. Most of my lenses came with hoods but I also have the rubber ones because they are useful when shooting through a window — so I frequently carry both.
Digital Photo Professional shipped with your camera, so you have a good editor even if you do not have Photoshop. GIMP is another good editor, and it is free, too.
A few of your photos have more dynamic range than JPEG can handle. Shoot raw, then you can adjust to compensate.
Pay attention to your backgrounds and the edges of the frame. The Rebel has a 95% viewfinder, so sometimes junk will intrude that you didn’t see in the viewfinder. Sometimes, cropping a little is needed, or the clone tool.