IMHO, your conversation with D was a great start. It is good that she is at least speaking to you about it.
I also think that your daughter needs to hear from you that you will love and spend time with her no matter how things end up. It is also very important that she understands that your R sitch is not her fault. Too often the kids tend to feel that only if they would have done x, or didn't do x, etc.
Me & H: 33 yrs S: 4 & 6 D: 2 M: 9 yrs ILYBNILWY: 8/09 SEPARATED: 9/09 The Beginning