Counting calories.

Hi I'm not new here in mfp, infact I lost 26lbs last year from 162lbs to 136lbs for 4monthsof diligently inputting my calories and slightly being active (cardio-4x a week).
However, June of last year I got pregnant and gained about 45lbs. From that gained I still have 24lbs left to lose to get to my pre-pregnancy weight which is 136lbs. (I'll be happy to lose more, my target is 130lbs).
But just like everyone, this time I'm struggling to do any active exercise because I feel so tired by the time I put my kids to bed, which is 3yr old and 4months old.
So I was hoping is anyone here lose weight just merely putting their calories in mfp? I started tracking my calories again last week. I don't really have a problem with my calorie limit except mybe one in a while when there's an occasion.
Thank you mfp community.