I think autoflowers have a harder learning curve because you can't make any mistakes. Any mistake slows growth, which in turn diminishes yield.
Look at this new pic, I'd say it is nute burn. Autos need less nutes, especially, in the beginning.
Personally, I wouldn't even try to save her and just start over as that much stress so early is going to result, most likely, in a tiny plants that produces so little it is not worth your time.
If you wish to save her, though, then first run enough water through her, at 6.5 and then use a shot glass under the pot to catch run off water. Test that water's PH. If it is much lower than the 6.5 you put in, then flood her with tap water or spring water. Don't PH it this time.
If it comes out higher than 6.5, then flood it with 6.5. No nutes yet. Just flood with water. Keep flooding until the runoff has the same PH as the water you put in. After that, feed with 1 teaspoon of Epsom salts per gallon of water. Give her four days to recover then feed with 200-300ppm of food.
Then the next time you feed, feed with just water, or water and liquid seaweed. Then next time feed with 400-500 ppm if she looks to be recovering well.
Firstime,
) ..
