If you can catch up on my sitch, you will see that I am not a model DBer, but if I felt it would have worked, I would have followed it to a T.
I did what worked for me...although I have to say, not always did it work, so I had to be careful. And the first couple of months were not good ...lol.

So, it is early on your path still. Continue GALing, looking good (always) and this is going to get back to your W, especially considering your situation of in laws being siblings lol!!

She drives by...wave. NO expectations. She doesn't wave back? So what? Smile and carry on.

Find one thing positive to say to her the next time. Not creepy, positive. "Is that new? It looks great on you....Did you get haircut? Looks great.." Stop there. do not go further, best at end of picking up kids or going home. No expectations then and convo doesn't go downhill.

Now, the drinking is worrisome in terms of the kids. Does she get them 50/50 or what is the schedule?
The above conversations are to open the door to the one where you will suggest that your parents (are they around) would love to spend some time with children, could they sit the next time?
or...if you would like to go out, I would be happy to have kids...

I am not saying this is a convo that will go well for you, she will feel accused. So you try to make it about you or your parents or an aunt or uncle...not her and not kids, because as mothers, we get p*ssed when someone insinuates we are doing a crappy job. Even if there is no accusation, we still know when we are failing our kids.

JUst MO, but as I said, you are early in this. NC is working for her right now, do not force hand.

Oh yeah, the whole "We could get back together" shows she has not seen the changes in you yet and has not acknowledged or began her changes either. Her drinking shows it...coping mechanism.

So you can reflect on what I've posted, but remember that your kids are first priority here, in terms of safety. Unfortunately your relationship may have to take a back seat to this.