I recently registered my family for the Nexus program - me, my wife (registered herself), and our two kids (I registered both). This was back in late August. The delay for conditional approval at the time was about 36 business days, from what I remember according to their website - so expecting to hear back from them in early to mid october.
I got my kids' conditional approvals Sept 28 and Oct 1. However, my wife and I still haven't heard back on ours. There's no change in our status - we haven't been declined, just not yet conditional approval. I've logged into each account to verify that I just didn't miss an email or something.
Is it common for adults to take significantly longer than children?
I received conditional approval a few weeks later, in early Decmeber. I never found out why it was that myself and my wife took so much longer than my sons' applications, and would still love to know.