Hi and thank you for your question.
Great question, in anticipation of the retirement.
You can do 1 of two things.
First, you can file with a stepped payment, where you pay X until she retires, then Y from then on for the rest of the plan, assuming you know what income she'll be bringing in at that time (pension etc).
Second, you can file with the payment reflecting current income, then bring a motion to modify the plan in 8 months when her income is reduced, and request the payment be adjusted accordingly.
You still have to meet the plan requirements to pay enough of the the debt based on your means test
-disposable income and asset protection, but either option would be available, but the former is easier as it is built in and you just change the plan payments as called for in the stepped plan.