Not for 20K. not worth it. That $ after tax will be eaten up by extra commuting, childcare, and unforeseen expenses. Plus, getting up to speed in a new job can take 1-2 years. You may have to put in extra hours in the beginning. Plus "the grass is always greener" or seems to be until you get there.
I've had several job moves, and the ones with just a $20K increase were more trouble than they were worth.
A couple years ago, I took a much bigger time consuming job for a 40% pay increase (and I have young kids). The first 2 years were really rough, but the pay increase was enough to make it worth it.