Okay, I have finished college and was halfway through graduate school when my daughter was born. One might say that if I finished school I'd be better off, but really, in my field I'd have to go back to school in order to work anyway cause a 20 year break would be a big detriment. Now I do plan to finish school within the next 5 years, but honestly I'm not even sure why cause again, if I choose to work I'd have to go back to school or take some sort of continuing education classes. I think in that sense (cause not many jobs allow you to just jump back in, at least not in a way you were many years earlier, before you had kids) all SAHMs are in a dangerous position. A friend of mine has been a travel editor for
National Geographic for over 15 years and has had to go back to work when her kids were all 3 months old or she'd basically be out of a job. If she took off a few years, or say 10, sure, she could apply for her job again but odds are someone else has it so she's out of luck. And she's 41 now with a 15 month old (and 5 and 9yos) so if she decided to be a SAHM with this child for let's say the next 4 years (at which point the kid will be in school), her old job will be gone and at 45 she's not so desireable as a new employee anywhere.
And yes, I agree with you no doubt that the OP would have an easier time waiting till after she and her partner finish school to have kids, financially that is. But even after they graduate, residents do not make a great salary, and there will be tons of loans to pay back, and that small salary will not go too far for living expenses so it will take quite some time to pay those loans off. So therefore they'd be best off waiting till they're both attendings, making the big bucks, cause then they can pay off the loans, the regular bills, and then start saving for retirement and the kid's education (2 kids in their case). But that's years and years away-minimum of 8 from now, well, from September, based on what the OP and partner plan on doing. And that's just when they'll get their first 'real' salary, so not even time to do all the things I mentioned like paying off the loans. To do that they'd need about another 3-4 years, so about 12 years from now, which for some would be a long time to wait, possibly too risky (since they want 2 kids and presumably want at least a 2 year space between then). And even at that point I'm guessing they still couldn't have saved up too much for college/retirements cause I know we have a couple hundred thousand in medical school loans from my husband so I'm guessing they will too (and whatever college loans they may have too).
So I do agree in waiting till you can support your kids, but waiting till the 'perfect' time just may not be possible for all. The OP is in a similar situation to me and we have an almost 2yo and another one on the way and we're doing okay. We can send my daughter to preschool, we'll be able to send her to college cause by then we'll have the attending salary so it won't be the issue it would be if she were 18 now, and we'll be young enough when our kids graduate college that we'll still be working (cause I do plan to go back to work after my kids are all at least 5) so we'll be okay for retirement too. In fact, it's because of the OP's profession that I wouldn't be too concerned about how much money I had before I had kids. She'll be making enough money in enough time that they'll be just fine.