She believed him to be addicted to hunting, and therefore horses must be provided for him.

He was a widower, and she remembered of old that he was fond of pretty women, and she knew that in coming days he might probably want money;--and therefore she had asked Madame Max Goesler to spend a fortnight at Harrington Hall.
Madame Max Goesler and Phineas Finn had been acquainted before, as Lady Chiltern was well aware.

But perhaps Lady Chiltern, when she summoned Madame Max into the country, did not know how close the acquaintance had been.
Madame Max came a couple of days before Phineas, and was taken out hunting on the morning after her arrival.

She was a lady who could ride to hounds,--and who, indeed, could do nearly anything to which she set her mind.

She was dark, thin, healthy, good-looking, clever, ambitious, rich, unsatisfied, perhaps unscrupulous,--but not without a conscience.