brickeye is correct - there is no federal exemption for interstate transfers with family members. A handgun
must be transferred to your daughter by a FFL in her state of residence. There is no federal requirement that you must have a FFL in your state ship it to a FFL in her state of residence-
some states require it (I don't believe either CO or CA is one of them) and some FFLs have a policy to only accept firearms from another FFL since many times a non-FFL sends the firearm with insufficient information for the FFL to log it into his bound book (a distinct problem), but there are no federal legalities preventing you personally from shipping it to a CA FFL.
A long gun can be transferred to your daughter by a FFL in Colorado. Verify that it is not an "assault weapon" under CA law.
You cannot legally just give it to her when she's visiting you and she cannot legally transport it home to her state without a transfer through a FFL.
18 USC 922 -
http://codes.lp.findlaw.com/uscode/18/I/44/922 - is the controlling federal statute. You and/or she will have to research the CA laws regarding the importation into the state of the particular handgun or long gun you have in mind -
http://www.calguns.net/ is a valuable resource in this regard.
The legalities and carrier policies of shipping a firearm to another state is a subject unto itself.