NO INTENT, NO FAULT. Stewie and Chiney appear to have stepped on each others feet as they position for a rebound and they both end up sprawled on the ground in opposite directions. The ball comes off in the direction of Chiney's sprawl and KLM leaps up not realizing Chiney is on the ground under where she will land.
I saw that other play which was sort of similar where one of the other Cardinal stumbles to the ground and BB ends up getting fouled in a similar way as she is undercut by the falling player and Chieny ends up avoiding stepping on banks but ends up stepping on her teammate. This stuff happens quite often under the basket when players are rebounding and it is always dangerous for the leapers - luckily it usually just results in a few bumps, occasionally a sprained ankle, and unfortunately sometimes in something more serious - head, knee, or arm/shoulder.
On Edit:
Interestingly, with the reduced physicality it might happen more often as it is harder to fall down/stumble if two or more bodies are really locked up and leaning on each other.