הלכה אויף ויקרא 21:2

He who has been bereaved of a relative for whom he has to keep the period of mourning is exempted from reading the Shema till he has buried the body, as his mind is not free for reading it. A watcher, even if the body is not that of a relative, is exempt from reading the Shema. When there are two watchers, one watches while the other withdraws to another room and reads it. Then he returns and watches while his companion withdraws and reads it. So too, one who is engaged in digging a grave for the interment of a human body is exempt, for the time being, from reading the Shema.

(In the case of) one whose betrothed (woman) died - if the betrothed man is a Cohen, he may not defile himself because of her, as it is written: “except for his relatives” (Leviticus 21:2), and this means near kin. And a betrothed is not his near kin, even if he has betrothed her by (an act of) intercourse, since she is (supposedly) prohibited to him (for further intercourse) until the marriage.
If he (the one who betrothes) dies, she is not obligated to defile herself because of him, even though it is a commandment to defile oneself for all near kin. Nevertheless, (defiling herself) for her betrothed man is no “mitsvah” (good deed) but doing it constitutes no prohibition, even if she is a female Cohen, for the daughters of Aaron were not commanded regarding the defiling, as it is written” “Speak to the priests, the sons of Aaron” (Leviticus 21:1); (it says) “the sons of Aaron” and not “the daughters of Aaron” (i.e. the prohibition against defiling oneself applies to men only).

All the dead [near-of-kin] mentioned in the Scriptural section⁹Lev. XXI, 2- for whom a Kohen¹ Glos. may defile himself, — [the law is that] it is a religious duty that he defile himself for them; and if he does not wish to [do so], he is defiled against his will.¹⁰Zeb. 100a. [This applies] both to the man and to the woman.¹¹If she is the daughter of a Kohen, she too is religiously dutibound to defile herself. Thus N, Asheri, Tur and v. Ket. 53a, Rashi s.v. ולא מיטמאת. According to Maim. (Yad, Ebel II, 6) this refers only to males and not to females. however, A.H. who offers a logical explanation of Maim. point of view and removes the contradiction betwwen Maim. and the other codifiers.