Couldn’t easily find out exactly but broadly speaking it means that there is suspicion that her bowling ‘action’ isn’t legal, probably that she isn’t fully extending her arm.
“The ICC defines an illegal bowling action as when a player’s elbow extends more than 15 degrees between the point when their arm reaches horizontal and when the ball is released.”
Couldn’t easily find out exactly but broadly speaking it means that there is suspicion that her bowling ‘action’ isn’t legal, probably that she isn’t fully extending her arm.
“The ICC defines an illegal bowling action as when a player’s elbow extends more than 15 degrees between the point when their arm reaches horizontal and when the ball is released.”
Cricket Europe article