your toddler is smart. she is picking up on your insecurities and worries over her behavior now. you are giving her the upper hand when you try to cater to her and be her buddy. this is short-lived behavior until she gets adjusted to her sibling. as our daughter got older and more animated and fun to play with, our son softened and enjoyed being around her. he actually taught her to walk by holding her up by her hands all the time as she took steps.
your daughter will come around and her brassness will diminish. i wouldn't try to buy her affection by doing stuff for her just so she'll toss you a bone here or there. i think that could be more detrimental to your bond than if you ignored her "i like daddy best" remarks, reassured your love for her, and reinforced your expectation of respectful conduct from her.
i imagine that all kids who aren't only children should grow up to hate their mothers because they had to share their mothers' attention. there really is enough love to go around. you know this, and she'll eventually know it too. she is still a baby.
the only thing you can predict about a toddler's behavior is that it is unpredictable. in a week, you may be writing a topic about how you are now her best friend and how she doesn't like her father! toddlers are crazy!