Actually this is very simple matter, more so if she was a visitor to the parish. The presider of the mass has full control and he makes the decision during the mass. That would include not giving Communion to your friend if she did not comply with his rule. .
That is not true. The Church (Rome) is the one that develops the rules. Certain authority is then given by Rome to the local bishop, to the celebrant priest and to the faithful.
Where the authority is given to the local bishop, the celebrant priest and the faithful have no authority.
Where the authority is given to the celebrant priest, the bishop nor the faithful cannot overrule.
And where the authority is given to the faithful ( such as the position to receive Holy Communion) neither the priest nor the celebrant can overrule them.
Aquinas defined the Virtue of Obedience as conforming one’s will to the will of the one who has the authority in that realm.
It is Virtue of Obedience in each to recognize where the authority lay and to conform one’s will to that.
The Bishop practices the Virtue of Obedience when a celebrant priest chooses to say the Mass under an option provided by Rome to the priests, even when the bishop himself would choose another option.
The faithful practice the Virtue of Obedience, for example, when they stand after the Agnus Dei of the local bishop has declared it to be so in his diocese, even if they would prefer to kneel. Rome gave the local bishop that authority, so we recognize that authority and conform our wills to that.
The priest practices the Virtue of Obedience when he gives Holy Communion to a kneeling recipient, even if they prefer that they stand. Rome gave the authority to kneel (or stand) to the faithful, so the priest is then required, by Obedience, to conform his will to that that decision.
Since we desire Virtuous Priests, we are to desire that they conform their will to the directives of the Church, even if they feel otherwise.
That is the way of the Church and the command from Rome,
The person who kneels (or stands) is practicing Obedience, is it too much to ask the priest to do the same?