I'm not an SLP but vocal folds can be locked in the open position which means air flow is still happening, but no phonation in the cords. If she's voicing a consonant, chances are it's the next vowel she is afraid of and is hanging back on. So I don't know what to call it but it's like she's not even approaching the vowel sound because she knows if she tries she will either block or it will be a scary out of control stutter, which she can't get yourself to do anyway.