Treat both equally. The English speaking will help the other lady.
a couple of suggestions. i have taught classes with non English speaking students. Theere are hand held electric translaters that some of my students have used, A good demo. Pictorial hand outs, anything having to do with numbers write down for her and every one else. Not everyone can grasp the numbers when hearing them. Also many seniors do not have the hearing of a younger person. If you do not do handouts use a blackboard. If your classroom does not have one get a small one for yourself to write on and draw sketches. Write down web sites for at home follow up. i'm sure she has a trasnslator to Chinese on her computer. Also she may understand more English then you see in the beginning. Never underestimate anyone
Physicaly hold students hand, ask her permission first. you will develop your own sense of communication.
i owned a retail business that occassionally had forgien visitors who did not speak English. When I wrote price down on a piece of paper they understood.