Fine, if they want to cling to that pansey “she excommunicated herself”,
then make a public announcement by an official spokesman (Bishop) to that effect,
and refuse to give her communion.
That’s how it works: the person proves themself incorrigibly heretical and the Church rules that the position the person has taken is openly heretical and a scandal to the faithful. They are then spiritually isolated by being issued a Bull outlining their errors and requiring open and complete recanting of the error and willingness to undergo absolution, penance and restitution.
That’s excommunication, operationally.