Jessica Alba is 'doing the right thing' and marrying her baby daddy Cash Warren.

PEOPLE magazine is reporting that the rumors are true and Cash has popped the question to Jessica.

The paparazzi caught Alba leaving with a big rock on her finger, and now her publicist has confirmed the news.

"I can confirm that they are engaged," says publicist Brad Cafarelli.

Alba and Cash have been dating since the fall of 2004.  They announced in early December that they are expecting their first child.