I hope =/

I meant that after we skip to a week after Pema's passing, Lin can come to Tenzin and reveal that someone's emerged who did not have bending and suddenly does. This could be the start of it, but Lin's trying to keep it a secret as much as possible. Then in the following weeks others are getting it and it's becoming impossible to contain and a public statement may need to be made about what's happening. 

That can work fine. Since Lin is keeping this investigation under wraps, Mako and Bolin wouldn't feel any pressure in letting her know Asami is bending.