If you're losing on what you're doing, I wouldn't worry about fine tuning yet. Personally I think the hardest part is getting started, getting moving. Once you're in the swing of lower carbs, you can fine tune if you're not losing at a rate that keeps you motivated.
A lot of people find that it's actually a lot easier to go extremely low carb (20-30g) because the ketosis helps reduce appetite dramatically.
And I agree you can indeed overeat protein, and the excess is converted to glucose, so if you're already eating a moderately high carb level like 100g it could be holding you back (but again, if you're losing well deal with this in the future!).
This is the calculator I use :
http://www.phlaunt.com/lowcarb/DietMakeupCalc.php
I'm in my mid-40s and have found I need to keep carbs around 30g (total, not net) and protein around 65g, about 1500 calories to lose at a rate that keeps me motivated. If I eat a little more the scale moves slowly but I get frustrated (like 1-2 pounds a month slowly) and if I eat low carb without paying any attention to the numbers (which is my preference) then I can maintain my weight without much difficulty, but I don't lose.
You're younger (I presume, since you just had a baby) so your body could be much more efficient than mine!