Utilize Their Strengths

Contrary to what the know-it-all might think, she doesn’t, in fact, know everything. But if she’s working alongside you, she (hopefully) has strong skill sets, which earned her a seat at the table.

Suggest that she be in charge of one branch of a project (budget, contracts, etc.), so that she can flex her muscles without infringing on others’ responsibilities. This gives them a sense of ownership and authority in this particular area, which can make them more amenable to other people’s leadership in other areas.