Leviticus 21:1-3 specifically prohibits a priest from burying a wife, may heaven forbid he should have such a need.
The structure makes this clear:
- A generalized prohibition (people)
- a specific exception (his survivors)
- a limitation on the exception to a specific list
The operative terms here are a) שארו, his survivors, the same term as is used in the laws of inheritance, property redemption and blood revenge, and b) הקרוב, they that are near to him, to exclude more remote blood relatives such as uncles and aunts, as made clear in the specific list.
Here, as in the laws of inheritance and revenge, a wife is not included. Presumably because she is not a blood relation to her husband and her bond to her husband can be broken by her husband and she has (presumably) "her fathers house", her own family from which she came, and who presumably bear the obligation to bury her should the need arise.
Note the cases of Tamar, who returns to her fathers house in her widowhood with no inheritance, Ruth and Orpah. The exceptional case is Ruth, who voluntarily leaves her father's house to stick with Naomi, despite the fact that she has no legal status as an heir (though she later reaps a spiritual inheritance, the house of David).