take your time and see where it might really be going is always good advice. The fact that you questioning is a good thing.
People can change. It is rare and it can take a lot of work, but sometimes acceptance and understanding can create a sort of a change just by building on the confidence and trust.
There is, even in a marriage that stays together with some success, many times the "waiting for it to happen all over again," ready for another dissapointment and an overiding reaction to every slight or action on the to be added to the whole and blown way out of proportion.
It takes work to learn to look at each mistake as it's own thing and not added to every other past issue.
Then the words become always and never. This is never true
People chANGING MAYBE NOT SO MUCH, BUT REALTIONSHIP AND PERSPECTIVE CHANGING can happen.
The initial learning of how to change some of the thinking is quite difficult, but when change is realized on a larger scale the new guidelines become a habit...
Take your time and hold onto your heart.
The kids involved does indeed call for restraint and forethought, but maybe you can make this progress without "getting back together" full time.
Much love and luck