910 and 909 Unheard-of Bear Behaviour

On September 5 2022, the first day of my visit to Brooks Falls, Katmai National Park, Alaska, I witnessed what was described by Mike Fitz, the Resident Naturalist of explore.org as "unheard of" behaviour by brown bears. Two sisters bears 909 and 910 had a cub each, the two mothers were "raising" their cubs together. Not only did they fish together and spend time together, they even were seen sharing eating one fish together. That was what I was lucky to watch in person.
Here is the story:
909 came with the fish, her cub (Bean) came right over and was eating the fish with her mama. Then, 910 approached slowly and 909 did not mind and let her sister 910 eat the fish with them. 910’s cub (Bead) was a bit further by the falls ladder and when she saw her mama eating she came over and joined the other three. 909 very quickly left and went back to the lip and continued fishing. 910 stayed with the two cubs watching them while they were eating. At some point when a male was approaching (this is not in the video) she made sure both cubs got away to hide behind the falls-platform. She was standing there with them making sure they are safe.
A very very special, incredible, precious two sisters and two cousins behaving like no other bears.