What does mingled her wine mean?
The Hebrews diluted their fermented (and unfermented) wines with water. Metaphorically, Wisdom is personified here, and what She is saying that the words of wisdom in Proverbs are to be meditated upon and applied progressively (thus mingled with water).
There is such a wealth of wisdom in Proverbs, that no one can apply all this wisdom immediately or overnight. Thus there is bread, meat, and wine used as metaphors for the various nuggets of wisdom. And the "meal" is a lifetime of seeking and applying wisdom.
Also, while Wisdom is presented here as a woman, the New Testament tells us that Christ is the Wisdom of God (1 Cor 1:24). Even though Solomon was the wisest of mortal men, in the end he acted very foolishly. That should be a warning to all Christians to apply these words of wisdom:
Keep thy heart with all diligence; for out of it are the issues of life. (Prov 4:23).