Felas I think what you're describing is the classic cross-fire between liberal and radical feminism.
Liberal feminism basically aims to make women the equals of men, within the pre-existing capitalist society. It wants women to have all the opportunities men have, but doesn't mind reproducing the inequalities and injustices within that system. For instance, capitalism has always allowed (encouraged) some men to be much poorer than others, liberal feminism is fine with some women being much poorer than others, or at least it doesn't immediately concern itself with trying to change that.
Radical feminism is more concerned with changing the entire system; it wants not just to balance out inequality between the sexes but to try to eradicate it entirely. To a radical feminist, therefore, the system of wealthier women employing (exploiting) poorer women is a problem, whereas to a liberal feminist it is not.
Liberal feminists would probably argue that no political movement can address all the woes of the world, and it's not their job to sort out the wider issue of economic equalities, which were largely created by and continue to be perpetuated by men.
Radical feminists would probably argue that, given that feminism is by definition based on some degree of solidarity among women, a solution which just improves the lives of wealthier women and leaves poorer women still being exploited, just exploited by women as well as men, isn't really an improvement.
My sympathies lie somewhere between the two. I think that the lives of poorer women probably are improved to some extent even by liberal feminism - legal and cultural changes to women's rights which have some degree of trickle down - but I am also pro a more radical approach to capitalism, and I think there's a natural affinity between this and feminism, due to the large burden of unpaid work which needs to be done and tends to fall on women, as several people have mentioned.