OK, so I thought this board was a board of intelligent WBB fans. As a non-Connecticut WBB fan, I get to bring some enlightenment.
The Official collegiate women's basketball rules per the NCAA:
RULE 9
Violations and Penalties
Section 1. Free-Throw Violations
Art. 1. After the ball is placed at the disposal of a free-thrower, it is a violation
when:
a - The free-thrower fails to release the try within 10 seconds and in such a
way that the ball enters the basket or touches the ring or flange before the
free throw ends.
b - The free-thrower purposely fakes a try or the free-thrower’s teammates or
opponents purposely fake a violation.
c - The free-thrower breaks the vertical plane of the free-throw line with
either foot before the ball strikes the ring, flange, or backboard, or before
the free throw ends.
d - The free-thrower enters the semicircle after the ball has been placed
at their disposal or leaves before the try contacts the ring, flange, or
backboard, or before the free throw ends.
e - A player enters or leaves a marked lane space or contacts any part of the
playing court outside the marked lane space before the free-thrower has
released the ball.
f - An opponent (player or bench personnel) disconcerts (e.g., taunts, baits,
gestures or delays) the free-thrower.
g - Any player not located in a legal marked lane space fails to remain behind
the free-throw line extended and behind the three-point field-goal line
until the ball strikes the ring, flange or backboard, or until the free throw
ends.
h - Any player occupying any of the legal marked lane spaces on each side
of the lane breaks the vertical plane of a lane-space boundary before the
free-thrower has released the ball.
i -
Any player occupying a legal marked lane space has either foot beyond
the vertical plane of the outside edge of any legal lane boundary, beyond
the vertical plane of any edge of space (2 by 36 inches) designated by a
legal lane-space mark or beyond the vertical plane of any edge of the lane
before the ball is released by the free-thrower.
j - A team has more than the maximum number of players permitted on the
free-throw lane.
k - An opponent of the free-thrower fails to occupy each lane space above and
adjacent to the block.
l - A teammate of the free-thrower occupies either of the legal lane spaces
above and adjacent to the block.
(Page 77)
The only rules violations involve contact of player's feet where it involves entitled spaces on the floor. There is NO rule violation for coming into contact with an opposing player in order to position for the rebound of a missed attempt. The determination of a player's positioning in relevance to assigned/entitled "marked lane spaces" involves the positioning of their feet in contact with the playing surface.
Opposing players have been allowed to engage in contact with their hands/arms/elbows/shoulders in battling for rebounding positioning - as long as the above rules are not violated - in both collegiate and professional basketball for literally generations. It is viewed as no different than two opposing players battling and positioning for rebounding positioning under the basket during a shot attempt from the field. They both have a right to the vertical spaces they occupy, and the right to fight to maintain that occupation.
It has always fallen to the officials to determine if any physical contact falls outside of the boundaries of "normal basketball contact" - a player cannot shove an opposing player aside, and cannot punch an opponent in the face and call it battling for positioning. But that interpretation by the officials have always been there, and for all aspects of playing basketball.
Boston did NOT push or shove Belibi into the lane. She leaned or pushed sideways into Belibi in the act of battling for rebounding positioning. Boston herself almost stepped into the lane - she was on her tip-toes when she leaned into Belibi. Belibi herself let herself lose her balance, and stepped into the lane prior to the ball leaving Brink's hands.
So the appropriate call for the event: no foul for Boston doing what the rules allow her and anyone else to do; a clear foul of lane violation on Belibi for stepping into the lane before Brink let loose of the free throw shot attempt.