is it possible to sell a house with a tennant, and grant that tennant the right to purchase ti home from the new owner?

I am the legal owner of a house in WNY my ex-wife agreed to purchase in our divorce settlement. She has not purchased the house, and I want to sell it. I suggested that I sell the house as a rental property with a tenant - that way she can stay in the house (there are children involved). She is concerned about retaining the equity she has put into the house over the last 6 years - improvements, painting, new roof, and other repairs. Is it possible to structure a rental agreement or some other document related to the deed that would give her the right to purchase the house at the end of a set period, or when the new owner sells the house? Are there any legal issues, pitfalls, etc., that I should be aware of in considering this option?