I doubt that law firms and banks are creating more family-friendly environments than academia, but I do suspect that it's easier to take a few years off in those professions. There's a perception that since science moves fast, a person who takes a few years out to raise a child will find their knowledge out of date when they try to return. I would argue that that's nonsense -- even in the super-speedy fields like molecular biology, you'd just need to curl up with PubMed for a while to catch up -- but that's the perception, and it's part of the reason I don't know anyone who's successfully re-entered science after a hiatus. There's also the problem that if you take a few years off you're not considered sufficiently dedicated to the profession, but that may be just as bad in law/finance as it is in academia.