Yes, the nature/nurture debate has been going on for years.
My DC never met my FIL and in fact he died when DH was 4 so he can't really remember him either. However, we have photos and have talked about him a lot and I think some of my DC may have inherited more traits from that side of the family than from mine.
My own father died when youngest DC was nearly 4 and she can barely remember him although she resembles him physically.
I think telling your grandchildren lovely stories about your DH, sharing photos and memories is the best way to let them know about his zest for life.
In the end, they will be their own person, they may be nothing like your SIL's family - or they may. That's just how it is and their parents will be the ones who are the most influence. Is your DD like her father? If so, I hope she will encourage them to swim in the sea, be adventurous, despite what her FIL said.
COUNTRY, CITY, AREA, PLACE -Game 21
4 Years On…..Health-wise, Has Anything Changed?