Redefining blessed: To receive a blessing from the Lord. It is a blessing to find a good wife or to be able to share the gospel. It is a blessing to have a nice day at word or to have your kids do something good that makes you proud. It would be quite a blessing to be healed by the apostle Paul. It would be quite a blessing to actually have seen and heard an apostle teach. What a blessing it would be to have actually seen the Lord.
To the Catholic church to be blessed is to: Be immaculately conceived, co redeemer, co mediator, dispenser of all graces, received bodily in heaven, ever virgin, possessor of 1000 names, etc etc etc.
So that makes it hard to even agree on a simple point. Catholics redefine and create language that would be infinitely better left in God's words as in the bible.
For one thing, it's a condition described in Jesus in the Beatitudes: "Blessed" are the poor in spirit, those who mourn, the meek, those who hunger and thirst for justice, the peacemakers, etc. It means God will vindicate them, make them fortunate or happy, they will receive God's favor. Opposite, "Woe to," the people who have bad stuff coming.
It's also a general adjective meaning good in the eyes of God. A blessed event, blessed assurance, blessed hope, a blessed relief from pain, the blessed departed, their blessed memory.
It's also an honorific title for good people who are thought to be in heaven but have not been canonized, like "Blessed Junipero Serra". It's also applied to God: Blessed Trinity, Blessed Savior, the Blessed Sacrament.
So the range can go from something simply good and fortunate, (a blessed break in the summer's heat) all the way up to the Infinite Godhead. Context will rule the meaning in every instance.
And there's no reason not to call Mary Bessed.