I'm with wayfarer on this one - kids will dislike things for any number of reasons, especially at that age. But it's always good to keep an eye on what's going on with them and just let them talk. Your kids are not old enough yet to try this, but one of the things I do is have family meetings every week. Kids really enjoy this 'formal' process and making an agenda and them taking turns being the 'chair'. I learn a lot about what's happening at school and at the other house without asking prying questions.
Because they're little, they don't have the range to articulate how they're feeling if your exW is all over the place and not spending as much time with them as you would etc. It'll come out, but it won't be sophisticated thoughts. Just keep your observation skills up high and you'll see how they're doing over time.
One of the other things I've come to realize is not the quantity of the time with the kids but the quality. Am I being present with them? Are we doing things that they enjoy? Even little things like taking a walk or lazing out in front of the tv etc is just still great quality time. So, I focus on what I am doing with the time I have with them rather than thinking the time I don't have with them. They'll remember the quality when they're older not how much time you spent with them.
There was a time when the schedule was a bit chaotic with the kids a while back. One of the ways I dealt with it so that kids wouldn't be anxious was to let them know who's picking them up that day and who's dropping them off etc. This way they knew beforehand and weren't left guessing. Just giving them information so they have control over the day and certainty. You're probably not in the communication space with exW to mention that, but hopefully she does that if her schedule is going to be unpredictable.
And I 100% co-sign on the parallel parenting that wayfarer talked about. I still parent that way even though now we have a bit more communication between us. It's a lot less stressful and you can make decisions without worry.
