Re: "...(if anyone has advice on how I can convince my wife to get chickens, please let me know)."

Learn from our government:  Give your wife one fertile egg; then ask her to incubate it under a light bulb;  then ask her to house it in the basement until mature enough to face outside elements; then ask her to feed it when put into the pen that she builds in the yard; then ask her to prepare the forthcoming eggs. [Omit what happens when hen stops egg production.]

Step 2:  Repeat Step 1 until the number of hens are what you intended to have in the first place.

Step 3:  You take credit should the plan go well -- blame her if it turns into a fiasco.

Step 4:  If a fiasco happens, tell her that pigs are easier.