Vectors question help (EMERGENCY)?

It's 1km wide and she swims 3km/hr, so it would take her 1/3 hr to get across. The river flows at 4 km/hr and she's in it for 1/3 hr. Multilpy 4km/hr by 1/3 hr and you get 4/3km downstream from her starting point. I'm confused by who lives downstream because you said Helen lives downstream from Helen, so I can't finish!