You and your family are the last Airbenders, there’s no way in the world I’m letting Amon take your bending away.
When Lin looked back, right before she jumped to the airship, I think she was looking back and imagining what it could have been like. Being married to Tenzin and having children of her own, raising Jinora, teaching Ikki how to be less of a spaz, and of course just dealing with Meelo. She got a taste of that right before the Equalists attacked and she regrets not being able to take that leap with Tenzin.
I really wish that Lin had at least one kid with Tenzin, just so that she could have the chance to be a mother. And of course so that child could join Korra on her journey.