What is the ruling on the prayer of one who doubted the emission of manī after waking up, then later became certain of it? And must she repeat the prayers she performed while in doubt? And is manī a light fluid that leaves no trace after drying except for the color?

The questioner seems to be afflicted with waswasah (obsessive whispering from Satan), and she should disregard it. A woman's maniy (vaginal discharge that necessitates ghusl (definition)) is thin and yellowish, and it may be white. Its characteristic is that it exits with pleasure and a subsequent relaxation in the body, and its smell is like that of palm spathe. If the questioner is certain that it is maniy, then ghusl (ritual bath) is obligatory. If she is doubtful, then it is not obligatory. Shafi'i jurists hold the view of discretion, and there is no need to repeat the prayers unless she is certain that it was maniy.