"when you were a child a gave you away" doesn't make sense as written.
Perhaps it is "when you were a child, I gave you away".
Which means "When you were a child, I gave you to someone else for good to be raised by them".
"give" by itself means simply handing something over to another person so they keep it.
"give away" has a few meanings:
1) give something freely and casually (often to multitudes) as a free gift, etc.
2) to reveal - what should be held secret is released (given) in the open (away).
3) to expose or betray - relinquish (give) out of the protection (away).
"giveaway" is a noun with the same meaning as above.