Identical surgery here.
Started off with Tramadol and something else I can't remember, those pills only lasted a couple of weeks, I took them on the alternate 4hours so that the lesser covered the stronger, a trick taught me by the hospital nurses when my CPA popped out on day one.
I thought I was a bit of a sook, but then thought 'why not ? it hurts and aches, take the pills.'
I used a stronger 15mg codeine/500mg paracetamol x 2 at night right through until about the 3 month mark, then cut back to less codeine (about 8mg) with paracetamol until the 4 month, then just the paracetamol at about the 5th month.
Daytime use was lessened a lot sooner. You forget, then realise that you've done without.
As Jo said, each of us is different, if your wife is still sore and achey let her have the pills, she won't become addicted, except if its Tramadol... then proceed with caution.
If she's anything like me, I get VERY grumpy when I'm hurting... :D