You're not supposed to add commemorations in the Pauline Rite. Chalk one up for the traditional Roman Rite which doesn't mind commemorations and before the 1955 reforms allowed a veritable boatload of them. Commemorations come in handy on a day like the 26th of August which in the Carmelite Rite is the feast of the Transverberation of the Heart of St Teresa shown in Bernini's well-known sculpture above. But it's also the feast of Bl Dominic Barbieri, the Italian Passionist priest who received Bl John Henry Newman into the Church. That's worth a commemoration for a parishioner of Bl John Henry Newman Catholic Church.
At least for a while north of the Tweed, the Pauline Rite appointed today as the feast of St Ninian, the Apostle of Scotland. All the liturgical calendars I can find now put him back on his old feast day of 16 September.
A collect for St Teresa:
Deus, qui illibata præcordia beatæ Virginis Teresiæ sponsæ tuæ ac matris nostræ ignito jaculo transfixisti, et caritatis victimam consecrasti : ipsa interveniente, concede; ut corda nostra ardore Sancti Spiritus ferveant, et te in omnibus super omnia diligant : Qui vivis. . . in unitate ejusdem. Amen.
O God! who hast pierced, with a fiery dart, the pure heart of the blessed Virgin, Teresa, thy spouse (and our mother), and hast consecrated her the victim of love; grant, through her intercession, that our hearts may glow with the fervor of the Holy Ghost, and that they may love Thee in all things and above all things, who livest and reignest with God the Father, in the unity of the same Holy Ghost. Amen.A collect for Bl Dominic:
Father, You chose Dominic as a minister of Your love so that his teaching and example helped many to find pardon and peace in the unity of Your Church. Grant that we may follow the same way of love and so gain an eternal reward. We make our prayer through Christ our Lord. Amen.
And so long as we are commemorating, if you save St Ninian for September 16, you'll have room for a third collect. I suggest St Bregowine, a Saxon nobleman, perhaps, and definitely the 12th Archbishop of Canterbury.