It is perfectly OK and some hold preferable to do Havdalah as you usually do.
Eishel Avraham 551; Chazon Ish (quoted in Imrei Yosher, pg. 4)
Some prefer a minor drink the wine.
The preferred minor for this purpose is a boy beyond the age of chinuch but who is not yet old enough to understand the concept of mourning the destruction of the Beis ha-Mikdash
Mishnah Berurah 551:70. [It is difficult to define the age of such a child.]
If such a child is not present, any boy under bar mitzvah age will do.