Merry Christmas to you as well, and I don't take your thoughts personally at all, but I have a feeling you don't have a performer or theatre kid. She does it because she really really loves it, but part of having an interest in the arts is wanting an audience too. One of her dreams is to be on American Idol someday, which I tell her over and over will probably be cancelled long before she is old enough to try out to be on the show.

She knows youtube, and understands that people put videos on and other people watch them. I'm impressed that she set an "attainable" goal. She didn't wish for her video to go viral or get a million hits, she just said she would like to see 100. That shows at least something close to realism. She is beyond thrilled that it has gone above 250- she wasn't asking or even hoping for more than 100 even after it hit her goal. This is "her thing"- at least for now. I think the kid was singing before she could even talk. I don't know if this is something she will stick with, but we will support her as long as it is something she really loves and enjoys doing. I really thank the Disers who did click on it, and certainly did not expect everyone to do so.
If she sticks with it, she is going to have disappointments. There will be lots of roles and solos she doesn't get and there will be performances when she messes up- just like for a sports kid they may not make the team, or get the position they want to play or may make a mistake in the game.
This probably won't ever be her profession, but there are a ton of professions that seek approval in one way or another. Most in the artistic areas do. An artist paints or sculpts because they love it, but they are also thrilled when they sell that first painting or sculpture and realize someone else appreciates their work. The dancers and the performers in the shows at Disney do it because they love it and they want an audience to love it too.An interior designer does their job because they like it, but their goal is also to get approval from and see the happiness of their clients. Anyone involved in any type of theatre or film production both behind the scenes and in front is hoping that their work finds an audience who appreciates it. A lawyer seeks the approval of the jury. They want the jury to like them and hopefully also to like their client and their case position so that they win. An inventor hopes that the world loves and buys his products. All of those are professions that seek the approval of strangers in some respect.
Also, you don't have to worry about her. She is an extremely outgoing kid with a strong personality, who for the most part doesn't worry about what anyone else thinks at all. (That is probably one of the reasons she has absolutely no fear on stage and never has- she does it for herself and if others like it that is all the better but she doesn't worry about whether they will). A joke around our house is that we don't really worry about her giving in to peer pressure when she is older- we worry about the calls we are going to get from other parents about what she has dragged their kids into. In 1st grade she had a group of her classmate girls tell her that she was too old to like the Disney Princesses, that they were for babies, and that she needed to give them up. She told those girls that she would like whatever she wanted to like, that they couldn't tell her what she could or couldn't like, and that she liked the Princesses. One of her teachers told us her prediction was that DD would either be a star or a CEO when she grew up.
Thanks for your concern and Happy Holidays!