responding to OP there are norms in the diocese for preparation, which is 2 years, following at least one year of basic formation. First penance in the 2nd year, usually in Lent, First Communion in the Third year. 3 parent meetings, 6 hours total, for each sacrament celebrated, with topics covered as prescribed by the Diocese. How each parish implements this and actually celebrates sacraments has every variation you can think of, including the local cultural practice of padrinos for 1st communion. Controlling variables seem to be size of class and size of church. Our pastor has specific reasons, well thought out, for first communion, with the child’s family, in the context of regular Sunday Masses, since the whole point is brining the child into the faith community through full participation in Eucharist, in the parish celebration. There is also the point that not every child in a class of 30 or so is ready at the same time, and that the parents are the best judgest of the child’s readiness.
if the pastor changes his mind, we build a bigger church, more parents complain or we get a new pastor, that could change overnight.
every DRE I know well enough, and I know about half of them well enough, makes sure children are instructed how to properly receive either way, and that they have the right to choose. that is not to say all pastors are as open minded.
the more parents are part of the process, through basic formation, sacramental preparation, celebration of the sacraments, and ongoing catechesis, the greater the likelihood they and other family members will respond to the graces poured out not only on the candidates, but their families, at this time. This extends to healing marriages, return to sacraments, completion of Christian initiation and other powerful effects. ooooh I love my job.