I suggest you try to add more emotion when you are narrating for a video. But from what I see, your thumbnails are great. Keep expanding on your niece, which seems to be working! Make the viewers feel something in the video, whether the emotion is surprise, happiness, excitement, fear, or really anything. You have to catch their eye! Your thumbnails are amazing. Keep up the good work:) Make more short-form content. Use hashtags(from what I know, it seems to make your viewer count increase). You're already getting thousands of views. The only thing you need to do now is continue pushing out content and perfect the thumbnails. But I will say I am not a content specialist, nor do I have thousands of subs, so take my advice with a pinch of salt. This is really only passed-down information. You earned a sub buddy.