Whenever you have a character name and then an animation in brackets, you need to have dialogue (or a thought bubble) directly on the line below it.
But if you dont want her to say anything, you could just have:
@JENNIFER starts dustoff_neutral_loop
or
@JENNIFER is dustoff_neutral_loop
or
&JENNIFER is dustoff_neutral_loop
That way, the script won’t be needing a dialogue with the animation.