An adjective for an expression/reaction/gesture that shows familiarity with what just happened?

I am trying to show that a character is reacting to a certain situation but are familiar with this situation and their reaction to it because it has happened to them before (perhaps even several times). This is the difference between for example smiling at something positive the first time it happens to you, but the fifth time it still makes you smile but you no longer have that first time surprise. It’s not that it makes you happy any less, just that the novelty is gone.

Here are 2 examples I am not happy with but that capture the same meaning:

• She smiled with familiarity seeing the landlord help the old
  tenant.
• An unsurprised smile broke across his face as the stray dog came running back again.