You say praying to Mary is wrong. That's a moral judgment.
And one that contradicts both the Bible and typical Christian practice.
If you ask someone to pray for you every Sunday at church, or you pray for someone else - then, according to Lisa's and Floss's argument, you're committing sin and idolatry.
But....
"as you help us by your prayers. Then many will give thanks on our behalf for the gracious favor granted us in answer to the prayers of many." - 2 Corinthians 1:11
"Is anyone among you sick? Then he must call for the elders of the church and they are to pray over him, anointing him with oil in the name of the Lord; and the prayer offered in faith will restore the one who is sick, and the Lord will raise him up, and if he has committed sins, they will be forgiven him. Therefore, confess your sins to one another, and pray for one another so that you may be healed The effective prayer of a righteous man can accomplish much. " - James 5:14-16
"But I say to you, love your enemies and pray for those who persecute you" - Matthew 5:44
All these, plus more, are "Biblical" examples of intercession. The exception with Mary is that she isn't your sisters-mothers-best friend, nor is she your Pastor or guest speaker.
She is, according to all forms of trinitarian Christianity - the mother of God. The most pure and holy of all women.