I'm so sorry to hear this.
It might do your daughter good to see you at least express something though. It might give her licence to express her own feelings. Even if you just tell her a bit about how you feel. Not an outburst necessarily. My husbands parents split when he was 13 and his dad never flinched, even though he was devastated inside. It took a big toll that he swallowed his feelings. My PN is still dealing with the ramifications of that today.