At the end of the day you fell in love with each other and brought kids into the relationship for a reason and married to commit to someone for life.
Unfortunately sometimes the person you fell in love with doesn't exist. It was a mask, because no one marries someone who appears unpleasant from the go-get. Once married / dependent, you see another side and the best thing you can do for everyone is separate.
I hated, hated the idea of divorce and stayed far too long in a very unhappy marriage.
Knew that I was right to be the one to pull the plug when my ex-MIL, a traditional lady who really wanted us to stay together for the children, said "You're better parents apart than you were together".
Having said that, agreed that a lot of people give up too fast. And divorce leaves a lifelong mark. It's still the least evil of the options though sometimes.
Either way I'm not entirely sure that women should put their marriage above their career; it makes them vulnerable in all sorts of ways. it's not so bad if you have a good relationship with a decent man, but there's a lot of users out there who'll dump you and the kids. that's why the CSA exists, such as it is.
OP, fwiw my ex and I started off by eating together now and then and doing days out. In the end we stopped, the main reason being that our oldest couldn't cope with it, he was desperately trying to get us back together, poor mite. We think that in fact it was better for him to stop the days out as it gave him false hope.
Every family is different, how to handle it may need to be adapted depending on the children's reactions. As people have said though, don't diss the other parent, remain polite and that will go a long way.