The first two terms 填房, 入贅 appear in Jiang Da Hong's Water Dragon Classic. In "Natural Water Method Song", there is one line that reads:
A Sinologist translated this as:
The screens are rolled up, the daughter will become a concubine and the son will live with the relatives of his wife.
This, of course, is not a word-for-word translation. This Sinologist has acquired help from a Chinese professor in Taiwan. I will explain the two terms and see whether you can do a better job.
填房 is actually a vivid term that describes the situation when a woman is married to a widower. After the death of his wife, the widower's bedroom is "empty" meaning without a woman. He will get someone to marry him to "fill the room". The woman is not considered a concubine. She is a wife but not the first wife. Only a not so well-to-do family will agree to have their daugher to become the "room filler" - marrying with a widower.
入贅 is another situation. Usually when a man gets married, his wife will come to live with him and his family (parents and brothers). If a wealthy family does not have a son but only daughters, then when a daughter (usually the first) gets married, the wealthy family will require the son-in-law to live with the wife's family and the first grandson born will inherit the family name of the wife. This situation is known as 入贅. Usually this man comes from a not so well-to-do family and he has brothers to be responsible to extend the family name.
This example shows the difficulty of translation as there is no equivalence in the western culture.