Women must at least recite HaMavdil‎{&&1}‎ or the equivalent on Motzaei Shabbat before doing work that is forbidden on Shabbat.‎{&&2}‎ There is a disagreement whether or not they are required to make Havdala. The issue is as follows: Havdala is a mitzvat asei shehaz’man gerama (time-dependent positive mitzva), and as such we would expect women to be exempt. On the other hand, Havdala is similar to Kiddush, as we sanctify Shabbat when it enters and exits. Since there is a special source that women are obligated in the positive mitzvot of Shabbat, including Kiddush,‎{&&3}‎ they should be obligated in Havdala as well. Yet Kiddush is more closely linked to the Shabbat experience than Havdala is. Thus, the exception to the rule exempting women from time-dependent positive mitzvot, which obligates women in Kiddush, may not apply here.
The Shulchan Aruch‎{&&4}‎ cites two opinions, but favors the one that obligates women in Havdala. However, the Rama, who serves as the primary authority for Ashkenazic Jewry, instructs women to avoid the issue by hearing Havdala from a man who is certainly obligated. The Bach‎{&&5}‎ takes issue with the need to hear it from a man, saying that a woman could always accept upon herself to make Havdala even if she is not obligated.
There are two additional issues that arise when a woman makes her own Havdala, which make it preferable to hear it from a man: First, there is a serious question whether she can make a beracha on the candle, as this is a time-dependent mitzva that is only tangentially related to Havdala.‎{&&6}‎ Second, there is a minhag that women do not drink from the cup of Havdala, which someone must drink.
In the final analysis, if a woman will not hear Havdala from a man, she can and should make Havdala, drink from the cup,‎{&&7}‎ and make the beracha on the candle after drinking.‎{&&8}‎ Even Sephardic women, who generally do not make berachot on mitzvot that they perform voluntarily, may make the berachot of Havdala when necessary.‎{&&9}‎
A complication pertaining to a woman hearing Havdala from a man (which applies even to a husband and wife) is as follows: If one has fulfilled a mitzva, he can perform the mitzva again for someone else only if that other person is obligated in the mitzva. Since a woman may not be obligated, a man who has already fulfilled Havdala may make it again only if it is on behalf of another male (even a male child who is rabbinically obligated) who has not yet heard Havdala. If such a male is not present, it is preferable for the woman to make Havdala herself, which is permitted, according to the Bach, even if she is not obligated.‎{&&10}‎