What is the ruling on one from whom the wetness stops for a short period after ablution, then reappears? Is she considered to have urinary incontinence, or must she observe the times of cessation to pray during them?

If there is no specific time for the discharge of fluids to cease, allowing for purity and prayer, then your ruling is that of one afflicted with perpetual discharge ( سلس ). You must perform ablution (wudu') for each prayer after its time has begun, and you may pray as many obligatory and supererogatory prayers as you wish with this ablution. You are not required to search (for cessation). This ruling remains until you are certain of recovery. These fluids are pure, according to the preponderant opinion, and thus do not necessitate istinja' (washing the private parts).