Par times are quite variable depending on several circumstances. You hammer out some of the circumstances by noting it was IDPA, 21 feet, and COM (which I assume is on and IDPA target and is the 0 circle).
The questions I have are whether or not you and your wife are wearing concealment garments and types of holsters being used?
A reasonable par time is to draw from concealment and fire one shot in less than 2.0 seconds. Follow-up shots should be no more than 0.25-0.30 seconds later.
Still in general terms, concealment garments will add about 0.50 seconds to one's draw if they are normal garments like vests. Sweatshirts where you have to pull up with one hand and start the draw with the other will add more time, about 0.75 seconds. Lighter weight covers, like an open front button shirt worn untucked over your gun will often be quicker than a vest because it offer less reistence and so it might be only about 0.30 seconds slower than wearing no cover garment, assuming it doesn't flop around and actually slow you down.
It has been my observation that folks carrying IWB will tend to be slightly slower than those carrying OWB. OWB folks usually find it a little easier to get a grip on their gun and are less likely to grab a handful of shirt as can happen with IWB.
You mentioned your wife's best time was around 3.0 seconds. That isn't bad if she is hitting her shots, but it can be improved. Something else to consider is that she may be fighting a problem you don't have so much, upper body strength. Drawing the gun and bringing it to firing position involves overcoming the friction of the holster (thumb break too?), gravity, and mass of the weapon. The initial draw is often slow because of having to overcome all three of those aspects, especially for some women or smaller guys who do not have a lot of upper body strength. Once the gun is in motion, then the upward travel has to be stopped, the gun orientation changed, and then the gun thrust forward to shooting position, somewhere in there meeting with the off hand. Then the forward momentum needs to be stopped as well. For a given size and weight of gun, the person with more upper body strength will be more likely to handle the gun better and faster than the person with less.
This is not to say women can't be quick. A lot of the problems of body strength can be overcome with a proper choice of weapon, holster, and then a practiced smooth style (very important). Ever noticed how some of the people look slow but have quick times. Those are the folks with some of the smoothest practiced styles.
There are other considerations. How good is hand fit to the gun? Also, hand size can be a factor in one's holster. A guy with big hands carrying IWB will have more difficulty producing a gun flush against his body than carrying OWB where the gun may be less flush or actually away from the body. The smaller fingers of women may make producing an IWB gun a little quicker for this reason, but longer glamor fingernails may slow things down.
So there are a lot of things that can influence one's time. So when you ask about what is a good par time, consider it in context. If you are just looking for the best time for competition, then you both can improve and maybe some of the information here will help with getting a better time. It can't be stressed enough that practice and a proper draw sequence are critical. After that, then making the right clothing, gun, and holster decisions can also affect one's time.