Why is it that no matter how much you try to love your MIL, nothing is ever good enough? She is always very distant. How can I bond with her? Any suggestions?

Maybe check with your Husband on her behaviour, is it normal? If she treats everyone than same than perhaps it's not your issue. Some people just do not appears to be very friendly but they are just warm in the heart. It's really good that you are trying effort to be engage with your MIL and trying to make thing works. Keep on trying!!