Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
None could know what Allah had decreed for this woman. This is a matter of the unseen that only Allah, the Most High, knows. However, if this woman chose herbal treatment after being advised by a person of experience on the matter, she did well. The fact that the cure is delayed could be for a wisdom that only Allah knows. The cure could be delayed because Allah wanted to forgive her sins, and raise her degree in
But, if she truly thinks that having an operation is better, and then she has to do so, seeking the help of Allah, and His cure.
She has also to make Ruqiya (Quranic verses and prophetic supplications read over a patient); this is what she is required to do.
This has nothing to do with whether the matter is decreed by Allah or not.
Allah knows best.