Should I accept maternity leave benefits for company not covered by FMLA?

This is not really a legal question--it's a matter of dollars and cents and also your personal risk tolerance.

One way to look at it: if you don't take the benefits, you will not receive any money.

If you do take them and can work for at least 6 months, you are ahead by that amount.

If you take them and can't complete the 6 months and need to repay, IF you budgetted correctly (did not draw on that money, but just kept in your bank account until you saw whether you'd be able to keep it for good), you are no worse off than if you never took the benefits.

The only way it appears you could get into trouble would be if you took the money, spent it, then had to repay it. If you are in financial position, and have the self discipline, to not do this, it would seem to make sense to take the benefits, since worst case, you will end up in the same position as if you didn't take them--and there's a chance you'll be able to keep them.