Answer:
   
   Traditionally, when a baby girl is born, the father notifies the
   synagogue officials of her arrival and of his plans to have her named
   at a service. Though the baby is not brought to the service, the child
   is named in the synagogue during the reading of the Torah on the
   Shabbat, Monday, or Thursday immediately following her birth.
   Sometimes the date is postponed so that the mother may be present.
   Typically, the father is also honored with an aliyah.
   
   The Conservative movement has no rule on whether or not the 8th day is
   a necessary day to hold the ceremony on for girls. The Conservative
   movement does encourage parents to hold a Simchat Bat for baby girls,
   and to view it as having the same importance as a Brit Milah for boys
   (see Moreh Derekh: The Rabbinical Assembly Rabbi's Manual"). More info
   is available from: "Jewish baby law"
   ([5]http://www.uscj.org/scripts/uscj/paper/Article.asp?ArticleID=271)
   
   However, just because there is nothing "official" doesn't mean you
   can't use an established welcoming ceremony or create your own at any
   time. Baby girls are just as welcome in Jewish tradition as boys are,
   and there are marvellous ways, in every denomination, of showing them
   they are equally loved.
   
   Note: The Reform movement has a number of ceremonies written and
   available through the Reform rabbinate; UAHC publishes Bat Brit
   certificates.