Nit'e Gavriel, Pesach volume 3, chapter 49, has quite a bit to say about this with respect to the semimourning period during s'firas haomer. I'll list some of his points:
2. Included in the prohibition on haircutting is cutting the beard, body hair, and hair inside.
3. One can cut a moustache that interferes with eating, or never-married girls' hair that [bothers] their eyes.
4. Eyelashes and eyebrows are not included and can be cut.
11. The prohibition on haircutting applies to a woman also.
12. A woman can cut the hair on her head short lest her hair grow long and certainly for t'vila.
13. A married woman can shave her legs lest she be ugly to her husband.
14. A never-married girl in the pangs of matchmaking can shave when necessary; likewise any bride for an engagement or t'naim party.
See also in chapter 50.
Edit: I had misread the question as being about s'fira; hence the above. Nit'e Gavriel, Mourning volume 2, discusses cutting hair while in mourning (chapters 3–6). He notes, in part:
Chapter 3, 16. A never-married woman who is planning to marry, and wishes to trim the hair on her head so it's not so long, may do so.
18. A married woman can cut hair short where she is accustomed to, as in a case of much hair, and certainly for t'vila. It is best, where possible, to do so with a shinuy (modification). [See also paragraphs 19–20.]
27. One cannot cut short hair whether of the head or beard or anywhere on or even in the body; likewise the peos of the head.
28. Hair on the lip or near the oral cavity which hinders eating can be cut short. But most lips' growth in thirty days doesn't hinder eating, so it's good to be strict.
29. Eyelashes and eyebrows are not included and can be cut.
30. Hair on a woman's legs — one can tend to be lenient and cut them, as it's ugly to her husband.
31. A female mourner can cut a wig, even while it's on her head.
32. Never-married girls of marriageable age can cut long hair over the eyes.
Chapter 5, 3. A kohen who must give the priestly blessing can cut his hair before three months [when people tend to remonstrate] so he not give the blessing with too-long hair.
