Is it permissible to sponsor an orphan girl and for the wife to breastfeed her, so that she becomes a محرم (unmarriageable kin) to the husband as her foster father through rada'ah (fosterage)?

Sponsoring an orphan has great good and immense reward, and it brings the sponsor close to the Prophet, peace and blessings be upon him, in Paradise. For the orphaned girl to become unmarriageable to you by fosterage, your sister or your brother's wife can suckle her, and she will then become their daughter through fosterage. This is more appropriate and safer than attempting to induce lactation in your wife, because the milk of women always prohibits marriage according to Imam Malik.