How to get ride of the belly fat.?

i am 19 yrs old. have 2 kids (no judgin). I noticed with my second kid its been harder to lose the belly fat. i am doing prettty good but hes 10months old almost and i wanna lose the bit i have left any good tips. I been doing crunches/situps/walkin (1-2 hrs) but now its gettin cold and cant really go out with the kids in it. i work 8 hrs and some days i get an hour at home before going to get the kids. so i just have that one hour to get what i gotta get done. PLZ HELP! i just want a flatter belly!