Hi Sophia,
Nice video. I’m a self-taught harpist too since this January so it’s cool to see another self-taught harp fan!
However, I took my first lesson in July after joining this forum, only to develop the proper technique and I can safely say it was the best thing I have done as a harpist because after my second lesson I found I could play pieces that before I had found difficult with so much ease and my hands looked a lot better when I played in front of the mirror.
I don’t know if you are considering lessons at any point but I highly recommend it. Some constructive criticism, make sure the palm of your left hand is pointing towards the soundboard instead of towards the strings as that relax your wrist and you can pluck the strings with your fingers with more strength, also when you are playing octaves with your left hand, it’s usually best to use the first finger (thumb) and fourth finger (ring) to pluck the strings inwards as the sound will resonate better.
I found using the fourth finger very difficult at first but with practise my left hand can now play more efficiently and it also sounds a LOT better rather now my fingers are trained! Good luck!