Hlaváčková was the top-ranked girls doubles player at the end of 2003. This was the last year in which there were separate junior singles and doubles rankings. Her highest girls singles ranking was No. 5, on 5 January 2004. In her U18-junior career she won three singles titles: a Grade 2 at Hostivar (September 2002), a Grade 1 at Frankfurt (June 2003), and a Grade 3 at Plzen (July 2004), and 15 doubles titles.
