I would not call it her “error” but rather, like our Lord, she grew in wisdom and found that this manner of receiving Holy Communion suffered from some very significant defects. And from the East to the West she did away with it.
This is one of the great divides between traditionalists and non-traditionalists. Non-traditionalists extrapolate from our current situation of extremely lax discipline that all of these permitted things must be perfectly fine, simply because they’re permitted. Traditionalists recognize the situation for what it is, a time of extremely lax discipline and harken back to more stable times and to the accumulated wisdom of the ages.
In this particular instance, there are very good reasons why the early practice of receiving in the hand was dropped in every single communion which can trace its origins to the Apostles, from East to West and why it was only dissidents likes the Protestant revolutionaries and groups like Call to Action which have tried to resurrect it. Pope Paul VI laid out seven excellent reasons, none of which Stromboli has acknowledged.