I am in the same position now. And I desperately want to get some weight off (I gained 30kilos this pregnancy) and am a bridesmaid in a few months and also want to ttc again later this year (so dont want to gain another 30 on top of the 20 I haven't lost). I was thinking Zumba also as DD4 could jump around also if we don't bump into each other (but I can't afford to buy it)

Can you try simple things around the home like vacuuming more often, gardening, mowing the lawn, opting to use the clothes line over the dryer (my bigger down fall around the house) I'm yet to try these stratergies myself but I am still in the thinking about it stage. How about go to the park and whilst the kids play on the equipment do laps around the enclosure? Do you have any friends locally that can go walking with you to help with the kids (like push an extra pram etc?)

I could have written your post myself. Above are just some things I'm thinking I could try. When I find the motivation to try it.