They yellow crest does signal that that baby is pied. Normals and whiteface tiels have grey crests, pied and lutino have yellow, whiteface lutino would be white.
According to the cockatiel color palette
http://www.kirstenmunson.com/cockatiels/index.htmlIf mom is what you say and dad is not split for pied, this would be what you should get:
Mother:Whiteface Pearl Split To Pied
Father:Grey Split To Whiteface
male offspring:
25% Grey Split To Pied Whiteface {X2: Pearl}
25% Whiteface Split To Pied {X2: Pearl}
25% Grey Split To Whiteface {X2: Pearl}
25% Whiteface Split To {X2: Pearl}
female offspring:
25% Grey Split To Pied Whiteface
25% Whiteface Split To Pied
25% Grey Split To Whiteface
25% Whiteface
If dad is split to pied (x1) then:
Mother:Whiteface Pearl Split To Pied
Father:Grey Split To Whiteface {X1: Pearl}
male offspring:
13% Pearl Split To Pied Whiteface
13% Grey Split To Pied Whiteface {X2: Pearl}
13% Whiteface Pearl Split To Pied
13% Whiteface Split To Pied {X2: Pearl}
13% Pearl Split To Whiteface
13% Grey Split To Whiteface {X2: Pearl}
13% Whiteface Pearl
13% Whiteface Split To {X2: Pearl}
female offspring:
13% Pearl Split To Pied Whiteface
13% Grey Split To Pied Whiteface
13% Whiteface Pearl Split To Pied
13% Whiteface Split To Pied
13% Pearl Split To Whiteface
13% Grey Split To Whiteface
13% Whiteface Pearl
13% Whiteface