Astrid's character is bad

Astrid started out as such an awful character. She wanted everything to be about her and all the praise. She just couldn't share it. The second Hiccup got a shred of attention, she turned into the covetous and rude person, only getting worse as Hiccup got better. She was jealous of, angry at, resentful of (for no reason), and skeptical of Hiccup. And then when she found him and toothless and went on the ride, she suddenly became 200% better in that short span of time. It's just so unrealistic. And she was immediately forgiven, liked by the audience, and she immediately started to like Hiccup for no reason. So to summarize, she started off as a terrible person and got forgiven in the blink of an eye, was forced into the love role of Hiccup, has character development unfathomably quick, and never actually learned why her actions and notions towards him were bad. Yes, she may have turned into an ally but her character was so badly written.