Should a woman who experiences (vaginal) discharge be treated as one of those with an excuse, ignoring the discharge that appears after the prayer, knowing that nothing came out immediately after istinja (washing after urinating/defecating)? And what is the ruling on suspending the intention to repeat the prayer?

If the discharge is continuous throughout the prayer time, or if the duration of its cessation is unknown, then your ruling is that of one afflicted with سلس (incontinence). You should perform ablution after the entry of the prayer time and pray with that ablution the obligatory prayer and as many supererogatory prayers as you wish until that time exits. What exits from you thereafter will not harm you. However, if the discharge ceases at a specific time that is sufficient for performing the prayer with a valid purification, then wait until that time comes and pray therein. If there is a possibility of it exiting after the prayer, your prayer is valid. And the intention to repeat the prayer, if it is estimated that something invalidating it might exist, has no effect on the validity of the prayer. Caution must be exercised against waswas (obsessive whispering).