It's not technically a step-parenting issue. Last weekend I took DSD to buy her school formal dress. I was really happy to do so, and enjoyed it, but I'm feeling sad and angry that her mum didn't. I don't know why, and I don't want to talk to any of the family about it as it will seem judgey. Her bf's mum and her sister are showing an interest by helping arrange hair and makeup. It's not about the money - DSD saved up for the dress herself so me and DP haven't contributed to that at all. I just feel sad that her mum wasn't there. What else can I do to be there for her without trying to take her mother's place?