“Wisdom rests in the heart of the one who has understanding.” The woman, Wisdom, comes to rest, or is, in the heart of a person with understanding. The one with understanding will obtain Wisdom.
“and even among fools she makes herself known” What the verse is saying, in harmony with the rest of Proverbs, is that wisdom will not be known by fools, but there is a caveat: wisdom reveals herself among fools, after all, everyone can learn what to do and what to avoid by watching what fools do and what happens to them.
Wisdom makes herself known even among fools although the fools themselves may never recognize her. Many wise people become wise by seeing the trouble and destruction that fools bring on themselves by their foolishness. In fact, some of the most profound lessons we learn in life come from seeing other people make mistakes rather than by making them ourselves.