Welcome here, I'm afraid I know little of traditional Chinese medication or treatments other than under some circumstances Medicare helps cover the costs of acupuncture. I do know firstly that your wife is going though a bad time right now, and that she has had post-natal depression for four years, recently going off her conventional medication.
May I ask your main concern? It could be many things from your wife's lack of improvement to worries over medication.
I'm guessing but I would think from your post there are two things, the first is that after 4 years treatment your wife has not improved, and the second is that she has become willing to try other things.
This is of course just a guess, I'd be grateful if you were able to correct any wrong assumptions.
Do you mind if I ask the reason for this change? Was it a feeling she was getting nowhere on ADs? Perhaps it might have been a side-effect such as weight gain. I do hope in any case she tailed off under medical supervision, otherwise the effects can be unpredictable.
Not all alternative practices and medications are incompatible wiht the types of treatment normally approved convention medicine as found in Australia. There are also a lot of different conventional medications other than one brand and strength of ADs.
Do you think it might be possible for her to visit her GP and discuss her reasoning and current regime. It may be that treatments from two different culture can coexist.
I do hope you come back and talk more