It's true that generally speaking men earn more income than women do, but the tax-free savings account is actually one of the things that will help women in those circumstances. First of all, the tax-free savings account, that $5,000, isn't tied to income. So if you're at home working, you're still allowed to accumulate that $5,000. The question of whether or not there are earnings there to feed into that is another one. But also, a spouse is allowed to contribute to the spouse's tax-free savings account. So the two individuals get it, and even though someone may not be earning, money can still be put into that account.
Also, a spouse can name the other person as the beneficiary upon death, so that amount gets added over and above what the other spouse's allowed amount is. So it doubles up, in a sense.