now you are speakig with an attorney, that is good.
No, she cannot make up her own rules against a court order, she must abide by them or face contempt charges.
unless she can prove you are a danger to the children, it is not likely she can restrict your boyfriend from doing as he pleases with his visitation time.
my advice to you as a person who has been there and done that and still wears the shirt....
step WAY back right now. if you give her no ammunition she will have nothing to shoot with. Do not communicate with the mother at all, let your boyfriend do EVERYTHING. there is really no reason for you to be involved at all. you are your boyfriends 'silent' partner when it comes to dealing with the ex.
"It is easier to build strong children than repair broken men." Frederick Douglas