hmmm is there any good instructor in singapore?
i did heard a lot of instructors in singapore are mostly out for the money instead of teaching the student correctly or correcting their mistake. like for my OW and AOW. i did not learn how to do basic recuse during my OW and did not learn how to use SMB during my AOW. and for the wreck dive, it's just bring us down to take a look at the wreck...
Either you've had the bad luck to find one of the less instructional groups or cus you've chosen the cheapest options and gotten a low cost operation. Either way get a new group for yourself.
For your wife, get her to do swimming more often as the more time she spends in the water the better, get a patient and good instructor (price isn't an issue here, safety is). Gideon Liew or Alan from livingseas are very respected instructors.