Ryan Phillippe and Alexis Knapp
Wireimage; Globe Photos
07/07/2011 at 03:00 PM EDT
There's still no official word on who the father
of Alexis Knapp's baby is, but rumored dad
and ex-beau Ryan Phillippe
was in the delivery room when the actress gave birth last week.
Knapp, 21, delivered a baby girl named Kai on Friday, a source confirms to PEOPLE, adding that "mom's doing great!"
A different source told PEOPLE in March
, "Ryan is aware of the situation [and] totally prepared to take responsibility should the child be his."
This child is the first for Knapp. Phillippe, 36, has two children, Ava, 11, and Deacon, 7, with ex-wife Reese Witherspoon
– Blaine Zuckerman and Dahvi Shira