For future reference, if she didn't crack the shells when she shoved them out, give them back to her & let her try again. You were only on day 2. No way to tell if they had even started to develop yet at that point without cracking them open & even then may have been too early to see more than a little blood speck. As for your current question, yes, sometimes it takes longer than the standard 21 days for an egg to hatch. It all depends on breed & the regulation of the temps. If it has been colder out it could even take an extra week to hatch. Lower temps slow development inside the egg.