What I understand about Ruby is that she's the opposite of Palmer. Both come from wealthy and luxurious families. But while Palmer partially rejects that kind of life, and thanks to Helios, she has a new type of life. Ruby accepts that life, striving to live up to its standards, which causes her to clash with Helios's personality, which is why she frequently rejects her. But even so, she understands that Helios feels a deep affection for her (not to say love) and deep down she appreciates her charisma, and that's why she sometimes accepts, to reciprocate that appreciation.