Disruptive? Abusive? Unprofessional? Bullying?
On the other hand: Her apologists might describe it as "being an effective advocate for her client."
There are a few objective measures you can reference:
The American Bar Association lays out what it believes are the professional standards of conduct for its members. You might review that and note some questions. E.g., did her behavior stray into "conduct intended to disrupt a tribunal" (3.5.d)?
The hearing officer (or judge) could have chosen to call it disruptive or even contemptuous, and since they didn't that tells you something.
This is a tricky situation: When a pro se advocate faces down a lawyer it's not fair. They know all the rules and have a bag of tricks they're used to playing. They have no incentive to pull their punches. A good judge can choose to mitigate this to some degree. Or they can simply say to the pro-se party, "You were advised to get competent representation; it was your choice not to. I'm not going to handicap the process because of your choice."
But in a hearing – especially a public hearing – everyone can see what's happening, and so you can call it by its appearance: The lawyer was being a bully. The lawyer was abusing her position as an officer of the court. The lawyer was neglecting her professional responsibility to, "avoid bias and condescension toward, and treat with dignity and respect, all parties, witnesses, ... and other persons involved in the legal process" (EC 1-7).
After all, the tribunal is (presumably) designed to produce a just resolution of a dispute. To the extent that the lawyer used her unilateral advantage in process to gain an advantage in the equitable resolution of the underlying dispute, you might simply note that. Again, in some hearings it could earn your side sympathy. In others it will just get a shrug and retort to the effect of, "Well if you didn't like that you should have hired your own lawyer."