Is a resting pulse of 64 healthy? i'm 5'3" and weigh 110lb.

Yes it is: A resting pulse of 64 is entirely normal and is assocaited with excellent longevity. For women there is a biphasic association of pulse and longevity. If the pulse is too slow, that can be a problem. Similarly, if it is too fast. This is just right. It may be worth considering how much your pulse increase with exercise as an overshoot in heart rate can be associated with problems.