I think Chelsea could've handled it better (hindsight being 20/20), ...but she responded the way she did.
I heard neither the question asked, nor the tone in which it was asked, ...so can't really say, ...in any event,
she chose to respond the way she did. Perhaps she felt that to give a different response might have
opened up a huge can of worms... I don't know. She responded the way she did, ...and that's it.
Personally, I think even if the question had been asked in a mean-spirited way, which may or may not have been the case, Chelsea missed a golden opportunity. On the campaign trail, or even in life, when someone throws you a curve ball, you have a fabulous opportunity to hit it out of the ball park. If Hillary or her campaign feels she responded innapropriately, that's up to them to deal with it and rectify that situation. Chelsea is Chelsea, she's not running for office, her mom is, and if her Mom feels Chelsea's response was appropriate, members of the public who would have preferred her to say otherwise will simply be disappointed.