Is it worth the heartbreak

So my SD is 14. I have been around since she was 5. My husband and bm was able to settle everything outside of court and she has always spend equal amount of time between the houses. Now she is in high school and wants to spend more time at her mom house than ours. Her mom throws money around and acts more like a best friend. We stick to our word and are realistic about our spending with her. She didn't want to come to our house tonight (it is our day) and her reason was she didn't feel good but she went to the gym and on a walk with her mom. I feel bad because my husband feels like he did something. I don't ever want to say give up on her because I do love her like my own, but I can't stand to see him beat himself up.