Who should play the children? (Spoilers If wewe Haven't Read Mockingjay)

Although they come in Mockingjay, who do wewe think could/should play Katniss and Peeta's son and daughter? I personally think that Frederique de Raucourt would be good for the daughter, and Daniel Divenere for the son. I know he is older than a toddler, but still.

Also, bonus question, who do wewe think should play the little girl in the Capitol who Katniss sees get shot down? She's on page 339 of the book. I think she could be played kwa Kayla Divenere, Daniel's sister.