Sforno on Exodus 2:5/ספורנו על שמות ב׳:ה׳

1לרחוץ על היאור. She had a view of the river, her room in the palace bordering on the embankment. No doubt, royal etiquette would not permit an Egyptian princess to actually bathe in the river. [the author was alerted by the preposition על instead of ב, “in,” in front of the word יאור. Ed.]

2ונערותיה הולכות, this is the reason why she did not command one of them to bring the basket to her as they were not with her at that time.

3ותשלח את אמתה, the servant who was attending her at the time when she bathed herself. All of this happened at the instigation of G’d so that she would not dispatch one of her regular attendants as she might mistakenly place her trust in them and such an attendant would throw the baby in the river.