Yeah, it's saying that she had to be at least 40, no less.

The other one means that he saved some money, but it wouldn't help him in any way. I know that that's pretty much what kalinka said, but it could also mean that he just didn't save enough money and he still doesn't have enough. Also, the construction goes, "for all the good (that) it would do him." You need the "it" and the "that" is optional in spoken english (at least around here).