Hmm. Well, actually it’s tricky. I believe that the Didache and very early prayers of the Mass (IN the Mass) included the “For the kingdom. . .” etc.
HOWEVER, anytime a Catholic prays the “Our Father”–as a stand alone, in a rosary, part of the Divine Mercy Chaplet, etc., the doxology is not included. Calling this prayer WITH doxology tacked on, “The Lord’s Prayer” is, if not ANTI Catholic, at the least certainly not PRO Catholic.
If you were given this booklet by someone, and you’ve looked it over, found this discrepancy, well. . .once somebody has given you a gift, it is yours to do with as you will.
Myself, I would do one of two things: Either burn the booklet (hey, it’s more thoughtful than putting it in the trash), or give it to someone Protestant who would appreciate it.