I think the Memoria Press courses come as close as you can get for now. Prima Latina is a full Latin course that doesn’t just include the prayers, but it does include prayers. (I don’t have experience with Latina Christiana) Then there is Lingua Angelica, which is specifically Christian Latin Music and Prayers. I only have the CD for this (there is also a teacher’s manual and a student book), but it includes the Sign of the Cross, the Gloria Patri, Table Blessing, Pater Noster, Ave Maria, Salve Regina, Kyrie, Gloria, Sanctus, and Agnus Dei, plus a number of latin hymns. This sounds like it might be just what you need. It is for 3rd grade and up, so if your child is younger (or at the bottom of the range), it might be difficult for them to do academically. But if you are interested in sticking with Latin, that’s ok - just start with learning the prayers and informally talk about what they mean, and then when they are old enough to do a more formal program, the prayers will fit right into their knowledge base.