Consult your own attorney, if you are already represented. If not, then may I recommend calling Law Office of Julie Plummer at 727-327-3020. They specialize in family law issues including custody disputes.
No, she cannot. In that event, you need to file a Motion for Contempt against your ex-wife (if you can have her refusal to allow visitation in writing it is better) and file it in court. Feel free to contact us for a free consultation.