When she saw her own serpent father and brother, Neel and tuntuni saved her
This is important because she finally saw her own father who had traded her and sent her away from him, and offended her mother. That was also when Neel had try and save her by almost being choked to his death and then Tuntuni drowned the snakes kingdom but then almost died.
Of course this was important because throughout the journey she realized how bad of a person she was for not listening to her parents and accepting them for who they were and they were almost killed but were thankfully saved by kiranmala. The whole story is literally about Kiranmala trying to save her parents from a very very dangerous place.
Kiranmala showed no interest throughout the book to neel but she did really like Lal and then we found out that all that teasing came to an end and they actually lived happily ever after and everybody got what they deserved. Kiranmala found out she was a princess, Lal and Mati were saved and could see each other all they want, and Kiranmala also found out she had feelings for Neel and so did Neel back. So her parents were found, she had a new crush, and Mati and Lal were saved. There was no reason for her not be happy. And for that, she lived happily ever after.