Well, the three bears represent a surrogate family for Goldylocks. The mother bear that is 'too cold' and 'too soft' represent's the Electra complex, where the 'daughter' grows to resent her mother. Similarily the father bear who is 'too hot' and 'too hard' represents the second half of the Electra complex, where the daughter 'lusts' after her father-figure.
This is again represented when she attempts to usurp the mother bear's place by sleeping in her bed, and then in the father's bed (or vice versa).
In the case of the baby bear, supposedly this represents 'penis envy' as in the original tale (Silvercurls I think it was called) the baby bear was a male. Thus by Goldylocks, stealing 'his' dinner, and then 'his' bed, she is usurping the position of the 'male' child.
Even in a more modern interpretation, where the baby bear is seen as female, or male, the argument can be made that the rivalry between the two young ‘females’ represent the conflict for a father’s love.