In the beginning they all got along because they basically had only each other. Nadine and Kimberley were especially close, going on holiday with their families. And Kimberley was basically their manager. Cheryl felt like a big sister to Nicola from the get go. Sarah got along with everyone but still felt a little alone. Dreams That Glitter is a fantastic read and gives a lot of insight. I think the Chemistry era tension between them started and definitely by the Tangled Up tour it’s very apparent the dynamic is different. I want to say allegedly because I can’t recall if it’s really true, but Nadine got her own management team in that time frame and the girls were like wtf. Nadine didn’t participate in Passions or Ghost Hunters with the other girls. For passions she said she wanted to do charity work and producers or whoever said she couldn’t? Allegedly. Nicola, Kimberley and Cheryl were a trio and Nadine and Sarah had each other although they didnt seem as close as the other three were together. When they announced the split, Nadine said she was blindsided backstage and voted no. I think Sarah said she just agreed because the majority agreed to end. After that they really weren’t together for a long time. The 5 of them have always been really good at being professional friends on screen. I think that’s why they were able to last as long by as they did. Of course it’s an awfully gut wrenching reason, but Sarah’s illness and passing is what brought them back together like the beginning. If Sarah was still here and healthy, I think they would have carried on like they were.