Honestly, it's a personal decision and one which you and your kids will have to live with.
My kid was 6 when I went to nursing school
and ended up separated from my spouse. It was tough, tough, tough to set her aside in order to do school but looking at it in the rearview mirror makes it seem a better decision.
Kids are resilient as heck and if you strive to carve out time for them - and they know that - the bruising is much more likely to your heart than to theirs. In all likelihood, they will ultimately respect you for the sacrifices that you all had to make in order to provide a better future for all of you.
You don't want them to look back 20 years from now and say, "Mom, why didn't you do it?" nor to suffer from the guilt that may bring on.