Just a few laws that will take effect during the week of Tisha BeAv, which begins on the Motzae Shabbat before the day of Tisha BeAv. Halacha does say that since it is the strongest of the mourning periods, which is the escalated level of the mourning period as we get closer to Tisha Beav, it is not permitted to take hair cuts, nor is it permitted to shave during the week of Tisha BeAv. Now, this includes the prohibition to children also. They should not take hair cuts. However, ladies would be permissible in cutting their hair during the week of Tisha BeAv. Chachamim did not make a decree on them.
Regarding cutting nails. If a person’s nails are a little long, which is above the skin line, Halacha says that it is permissible to cut them during the week of Tisha BeAv. Preferably, one should cut their nails anyway for Shabbat, and therefore they can get around all problems and fulfill a Mitzvah. But if during the week, somehow the nails are a little long, so it would be permissible to cut them during the week of Tisha BeAv.
Ladies that are going to the Mikveh during the week of Tisha BeAv, can cut their nails under all circumstances.
A man that has a mustache that is a little long, that’s interfering with his eating, it is permissible to trim it also in order to alleviate him, to eat comfortably.
***It should be pointed out that these halachot apply when Tisha BeAv falls out Monday-Thursday and not Motsei Shabbat.