Weight gain

Does it mean that I am not on my set point if I still gain while trying to eat after hunger cues?

I try to eat at least 2500kcal and therefore add up the calories in the evening. I often have to add a bit in the evening to get to those 2500-2600 calories. Would it be okay to eat less than 2500 if that was what my hunger was? (Still over 2000!)
I'm roughly BMI 19, no starvation symptoms (I think), 16years old and quite short...

When you stay sedentary and eat about 2300-2400 that can be okay, but it's hard to say that and it could trigger a relapse. But if you're still gaining means that your body wants to gain so just let it. It's maybe just an overshot so it can repair some left damage or you haven't reachef your set point yet.

I would stay on 2500. I have no starvation symptoms anymore, but I still eat 2500+ every day according to my hunger cues (even if they led me to 2000ish, I always sneak some extra nuts, juice etc in) to make sure I get enough and I still gain a bit.
Like jennysrecovery said, this could be an overshot, so keep on eating, this WILL work out. BMI 19 is very rare so it's possible that your set point is higher.

Ganz viele Grüße <3

BMI 19 is barely in the 'healthy' range and is most likely not your natural set point. Also, 2500-2600 is not exactly a lot for a growing teenage girl, especially one that is recovering from an eating disorder and whose body probably still has repairs to do. I don't think your hunger cues are excessive at all so you definitely should follow them. I would say stay on that amount.

Only roughly 4% of the population have their set point weight at BMI 18,5-20. And less than a fraction of 1% (!!) have their set point weight at BMI 18,5. Most of us land at BMI 23-ish.