I'm not disagreeing, it's completely against the spirit of the game.
Within the spirit of the game a warning to batter from bowler is usually sufficient to stop excessive backing up. "Next time, I'll take the bails off". This clearly wasn't done, so first offence equalled game over.
But there was a loss of concentration from the batter, keen to get on for the potential quick single, and she wandered down the crease. No problem with that with a fast bowler, but a spinner has more time to see what's going on. Which sadly she did.......
Underarm bowling, aluminium bats, bouncers at tail ender's, batsmen not walking.......stick this on the list