What is the ruling on the prayer of one who was splashed with a spray, and did not ascertain whether it was urine or from the bathroom floor that had urine on it, then proceeded to turn on the faucet with her hand while carrying the spray, and suspected the impurity had transferred to her clothes?

It is not necessary to wash the body or purify a spot suspected of being impure, because the default state is purity. If you doubt whether urine spray has hit you or not, the default is that it has not. If you doubt whether what hit you was urine spray or water droplets, the default state is purity. You are not required to remove your clothes when relieving yourself. Rather, you must ignore obsessive thoughts (waswas) and relieve yourself normally, building upon the default state, which is purity.