It is true, poverty is not a barrier to the I-130. It is a barrier for what happens next, the I-864 and interview, but that is overcome by getting a joint sponsor.
Note that because she is not a citizen, her husband who is outside the US will have to wait a few years (currently the backlog for spouses of permanent residents is 3 years) to be able to move to the US and get a green card. If she is eligible for citizenship, she should apply ASAP so her husband won't have to wait so long outside the US.