Promotional 1 / 3

At long last, meet Kailani Merizalde Phillippe Knapp!

On Monday, "So Undercover" actress Alexis Knapp, 21, shared an adorable photo of her 3-month-old daughter with ex-boyfriend Ryan Phillippe, 37. "I do declare you to be the prettiest lil girl in the whole wide world," Knapp wrote.

PHOTOS: How Ryan's kids have bonded with their new stepdad

Knapp announced her pregnancy at an industry event in mid-February -- five months after she and the "Lincoln Lawyer" actor officially ended their on-and-off relationship. (Phillippe was dating Amanda Seyfried at the time. They have since split.)

PHOTOS: Ryan and other hunky, shirtless dads

Though Phillippe has not confirmed his paternity -- as of July 25, a source told Us Weekly he had not taken a DNA test -- he's found support from his ex-wife Reese Witherspoon, 35, with whom he has two children: Ava, 11, and Deacon, 7.

PHOTOS: Star dads on duty

"Reese feels bad Ryan has to deal with this," an insider told Us at the time. "They're bonding over it because it obviously affects their kids."

MORE FROM WONDERWALL:

Alexis Knapp Gives Birth to a Daughter

Baby-Making, L.A.-Hating and More Star Talk

Celebribabies of Summer 2011