Tennis Tournament Draw

How is Ashley Harkleroad in the main draw of Miami without a wild card?
The Main Draw Tournament Women was published in Miami. Ashley Harkleroad is Alicia Molik in the first round. Harkleroad not win tennis in more than a year. I know she took time off to have a baby, but how is it that in the Main field, but not as a qualifier and not as a wild card entry? Why it's not like wildcards Clijsters and Henin need, when they came back from significant time away of the pro tennis?
Ashley Harkleroad left the tour in July 2008 and gave birth to a son March 2009. She is entering the tournament with a protected ranking. A Ranking is protected, where a player with a doctor confirmed injury or disease in the rankings for some time while the player recovers protected. Harkleroad in case their ranking was protected while she took a maternity leave. Clijsters and Henin retired voluntarily so that they do not qualify for a protected ranking.