While it's ok to point out possible bad behavior you have to admit you can't be sure. Yes it may sound suss but there is also a chance that its not. Maybe he is controlling and not offering his partner the support she needs but on the flip side it's also possible that this girl found her life at a dead end and looked for a way out, some people have been accused of getting pregnant so they can receive free support from the government, it's also possible she saw a guy with potential for success and a good heart, decided to stop the pill get pregnant and become a stay at home mom knowing he will always stick around to care for them, and no matter what happens now that theu have a child she got a hold on him OP did mention the girl said if he wanted anything to do with the child he had to come back from Brisbane.
I don't think that story is any less likely that that OP is a controlling partner who like to toot his own horn.
There are lots of sahm who have also suffered PND, it sounds like this woman has a lot of support, even with a controlling partner I don't see why she can't make dinner once a week....on one of the two days she is baby free.
Plus OP said he overheard her saying 'im in no rush to get back to work we are getting by'
Theres something to be said about that.