Service

Chinese society is patriarchal. In a family with sons and daughters, the pecking order is as follows: Males in order of age descending, followed by females in order of age descending. So a 5-year-old son outranks his 35-year-old mother (and the father will let both the mother and son know this). Young women are at the bottom of the pecking order, and they will be made aware of it constantly. In recent years (one child policy) this has gotten even worse, and the phenomenon of spoiled rotten sons has a name: Little Emperors.

Her parents are unlikely to approve of her marrying an American. The "most-desired" marriage would be for her to marry a man 5-15 years older than her, Chinese, rich.

The economic opportunity of her becoming a U.S. citizen may make up for you not being rich, I don't know.

Always be polite. Do not address her parents or anyone a generation above by their first names like in the US, unless they explicitly invite you too (this is not likely to occur). Vice versa, your gf will probably be uncomfortable calling your parents by their first names.

Sex-wise, her and her family are also likely more conservative. Expect to always stay in separate rooms, or at least say you are, even when she is visiting you. You will not likely be invited on vacations etc. until you are formally engaged or married.

When visiting, always bring a gift for her family. Your girlfriend will probably do this too.

Try to learn a couple of phrases of Chinese, this will greatly impress the family. If you have difficulty with the tones, try to think of it more like singing than speaking.

As for your being a gui lo...this will really depend on her family. For example, my parents always said they wanted me to marry a Chinese guy, but they totally love my white bf

The one thing I would recommend for any non-Chinese person trying to win over a traditional Chinese mother/grandmother is that you be honest in your love and sincere in your promise to be a good spouse/partner. Can't just say it - you have to just do it. Repeatedly.

Be cognizant of language differences, compliment the food, eat until you're stuffed, and be patient. And good luck.