The female counterpart to the term webmaster.
Some also use the term webdiva.
Any girl that has her own website is technically a webmistress, although
that does sound like it should have a hidden sexual meaning to it...
Surprisingly it does not, crushing the hopes of all teenage geeks who
once believed that a softcore pronographic picture of a woman downloaded
from the web could be called a "webmistress". Damn.