Bonding with my mare?

You could try maging her and giving her a horsey spa day. I do that sometimes. You could try join-up too. I agree with the others. Spend time in her stall, touching her, grooming her, talking to her, and maybe singing could work. Make sure you're always confident around her. But never look her straight in the eye when walking up to her. It is mating season for other horses so she could be a little moody.