As with all advice it is good to take it under advisement, but keep in mind it is not the be all and end all for every single person.

The 6 week guideline is there for reason, generally tissues in the body require that much time to allow them to heal. Consider when you break your arm, your arm is put in plaster for about 6 weeks as it takes that long for the bone tissue to heal. The same can be pretty generally applied to you abdomen and uterus. The tissues which have been cut need a decent amount of time to heal. Any exertion on your part cause damage.

That said, we all heal at different rates and all have different thresholds of what we can manage. There are certainly some people who are able to get back into the swing of things really quickly and some who are at the other end of that scale. Most people seem to be pretty able to manage carrying their little one in a sling among other duties, however I have certainly seen a case where someone ended up back in hospital with some pretty serious internal bleeding due to trying to do to much.

I carried my DD in a sling for a bit at the 2 week mark post c-section and I felt ok at the time. Afterward I was absolutely wiped out (I was quite surprised how exausted) and eventually ended up with a problem with the scar healing and an infection. I don't know if that complication had anything to do with my sling wearing though!!

I guess what I am trying to say in a round about way is take the guidelines under advisement but do what feels right for you! Keep an eye on your DP and do what you can to help in every other way so that she can expend the energy carrying your precious DS in the sling. You are right, it's a cosy little spot to hang and she has a reason to be jealous