The Difficulty Solved
And Peter said: “Let not wickedness have dominion over us, finding a pretext in Providence and your affection for your mother; but rather abide this day in your fast, and I shall join you in it, and tomorrow she will be baptized. And, besides, this hour of the day is not suitable for baptism.” Then we all agreed that it should be so.
Source: Clementine Homilies (New Advent)