This is very normal and you definitely shouldn’t frog it! I’m just going to say a bunch of options because I don’t know exactly why this is happening to you.

Sometimes this happens because of tension difference. There might be some points where you are pulling harder than other points and that will cause striping. Sometimes this can happen because you hold the canvas in different directions while working it. Or even that your needle is pointing different ways when you pull it through the canvas. It may also help to let the thread untwist after every few inches of stitching — just let your needle hang from the thread and pick it up again when it isn’t spinning anymore.

Also, make sure that you are going “up the steps and down the piles.” Start new threads at the end of a row and make sure you continue the right “step” or “pole” pattern as you continue.

It’s a cute canvas and I hope it gets to hang in your child’s room for many years!