With the second, I either lay it on with a bit of humour, "oh yes, woe is you. Nothing nice will ever happen ever. You have the worst life in the whole, wide world and I'm the meanest mum." Or, if I'm lacking in humour, "yeah, enough already with the hyperbole."
Negative language doesn't necessarily mean they don't have a can-do attitude. It just means they don't express it verbally.