all Christians are saints, that’s clear in scripture too. It’s also clear about having no other gods before him and who to worship and pray to.
You are thinking "pray" is synonymous with "worship" or "adore". That's not so. In the Greek, you can see it more clearly: "latria" means worship, "dulia" means honor (as in "honor your father and your mother,") "hyperdulia" is the highest form of "dulia."
"Latria" is offered only to the Supreme Being (God); "dulia" and "hyperdulia" would be different degrees of honor which may (in fact, according to the Commandments, must) be offered to humans worthy of honor.
As St. Paul explained, "Give honor to whom honor is due, custom to whom custom, tribute to whom tribute," etc. (Romans 13:7). That's why it's necessary to recognize different levels of legitimate honor.
Anyone who "adored" Mary would be guilty of wrongful latria: idolatry.
Christians knowledgeable about these distinctions understand that.