To the OP, I like how you let her evaluate which laptop to keep. And she chose for practical reasons not newness, price tag, or cool factor.
Also, to be fair to your daughter, your title is misleading. You didn't just "give" her a new MBA, she had to give up her fully working MacBook to keep it. Like telling her you're upgrading her teddy bear and to hand over the old one. Hence, you got the reaction you got. Next thing is to teach her to be more diplomatic, but I say just enjoy this stage right now when she is able tell you what she really thinks.
Also, to be fair to your daughter, your title is misleading. You didn't just "give" her a new MBA, she had to give up her fully working MacBook to keep it. Like telling her you're upgrading her teddy bear and to hand over the old one. Hence, you got the reaction you got. Next thing is to teach her to be more diplomatic, but I say just enjoy this stage right now when she is able tell you what she really thinks.