So we all know there was that one time where Grace called Steve "Uncle Steve" in episode 1x23 when he went to pick her up from school while Danny was in the hospital...
I'm wondering if it was out of respect (like how Kono referred to the old lady as "Auntie" in episode 1x12 when she was waiting for Steve to come back from stealing borrowing the money from the HPD asset forfeiture locker and how Chin introduced himself to Grace as "Uncle Chin" in episode 1x03 at the football game)
or
If Steve and Danny are that close that Grace would consider him like an uncle.
and also, if there's been any times where Grace has called Chin "Uncle Chin".
These are things I wish they'd put in the show.