Re: but for love
I don't think it is phrased very well. It would be better expressed as "the dilemma facing her heroines was whether to marry for love or for money". As the writer says, respectable women in Jane Austen's time were expected to get married, since they had no real means of supporting themselves independently. A dilemma is a situation requiring a choice between equally undesirable alternatives, so they might find themselves having to choose between a penniless man whom they loved, or a rich man whom they did not love.
I'm not a teacher of English, but I have spoken it for (almost) all of my life....