Hi there and welcome!
I'm 43 and the proud mom to a 2 1/2 year old (and a 6 and 8 year old!)- so I can totally relate to what you're saying.
I also find it much harder to lose weight now than I did pre-kids.. I never have the time to really focus on things, it feels like. I think you have to do the thing that feels the easiest for you to manage - for me, it's calorie counting. I use livestrong 'myplate', and while I don't keep up every single day, I do most days. Sometimes I even fill in the previous days worth of calories before I start the new one. It really keeps me honest, and also, nothing is off limits. But I do have to account for everything.
So when I make the kids a snack, I join them if it's a healthy one, or I have a part ofwhat they're having - whatever fits into my calorie goals for the day. I aim for about 1500 a day, plus 1/2 hour of exercise most days. That part can be problematic, now that my 2 year old no longer loves teh stroller. So what I now do is exercise outside the door to my bathroom - where he is sitting in the big bath playing with a ton of animals and toys. I can see (or hear!) him at all times so it's quite safe. He's happy and I can squeeze in 25 mins or so.
When my other kids were this age, I used to wait til they were both in bed, then left daddy in charge while I went out for a 1/2 hour walk/jog. I also really enjoyed that time to myself. I lived in the country at the time so it was really a perfect scenario - now I'm in a city of 6 million, so... not so much!
Anyhow GL and looking forward to talking to you more!