Hera never wanted kids of her own; it wasn't that she hated the idea of being a parent, she just never thought she'd be any good at it.

Kanan had grown up as a Jedi - avoiding relationships and other complications - and even once the Order was gone, he never expected to form a solid enough relationship that children would be in his future.

Yet, here they both are, with two children (not to mention a droid and Zeb), their lives in chaos, being hunted by the Empire, and neither one of them would change a single thing.