The first two chapters were good. You introduced the story well, and Tian is growing to be a 3rd dimensional character.
However, I am finding the pacing too fast. Everything seems to rush the story forward. You also do a lot of telling in regards to her career and her first love. The third chapter is where these problems manifest most clearly.
She did not yet know it, but Ying and Enlai had also survived.: Cut this sentence, you need to stretch the tension. This sentence basically negates any tension you could have been building in this chapter. Is this a short story? I will give you advice based on the assumption that it is.
She was barely alive when the ambulance brought her to the hospital. Although her condition improved after several days, she was distraught--Enlai and Ying were missing and presumed dead. She had not slept for two days and was beginning to lose hope when the news came--both Enlai and her daughter had been found--alive.: This paragraph needs to be stretched. Paint a picture of a few of her hospital stays, you are telling the reader too much. I want to experience her pain and anxiety. Make her wait, then reveal. I would dedicate chapter three almost entirely to her hospital stay, build the tension until chapter four, and somewhere in that chapter you should reveal that they are, in fact, alive.
The next scene in the garden should also be moved to chapter four. The pacing is much too fast, this story needs tension and drama but you aren't lingering long enough on the emotions. I understand she's distraught, but I just don't feel it.
In my opinion, you should show a day at work, or a day practicing lines while trying to take care of Yin at the same time and fulfill her duties as a marital partner. You touched on this in chapter one, and I could sort of feel her anguish, but not really. Again, in chapter two this should be lengthened. However, I did find chapter two to be the best in terms of pacing, tension and emotion, but it still needs work. Stretch her day at the beach, give her bliss before terror. A good way to stretch tension is to break something off until the next chapter. For example, you could make mention of the wave coming up the beach, and then cut to a flashback. The next chapter would show the waves engulfing its victims, her attempt to save Yin, etc.
The third chapter tells too much too fast. I don't feel her anguish at the hospital, she needs to wait for the good news, I need to see her sitting in bed sobbing because she thinks she has lost her second love and her only child. Don't tell me any of this, show me! You also rush too fast into meeting the boy at the courtyard, and the butterflies makes the scene all too obvious. Insert more mystery here, withhold more information.
I do want to say though that you have talent as writer. You have the "bare bones", as they say. You're very good with character development which is the element that most writers struggle with. That's an extremely valuable skill that you should be proud of. Your grammar is very good too, you just need to work on the storytelling aspect.
http://resource2.rockyview.ab.ca/ela301/related_readings/the_painted_door.pdf This is one of my favorite short stories. Read this, study it a little bit, and see how Ross paces the action. Not a lot happens in this story, there are only a few major events, but he stretches it on for a perfect fifteen pages. Your story has more action, more that needs to be told, so you will have to set your pace accordingly, but what you should really look for in "The Painted Door" is the tension-building.