Help! my bffl is about 2 become my sister!

thanks x the problem is is that my friends mum just died about 3 months ago. yesterday she said she was angry beacuse her mum died and her dad just suddenly came in a relationship with my mum, but my mum and her dad still love eachother. what should I do?

That's an issue she has between her and her father. You need to encourage them to sit down and calmly, and maturely discuss the issue like two adults, while keeping in mind that it's not any of your business. Your friend misses her mother, and you need to be there for her, but at the same time, she's upset with her father, and you need to let them work that out between each other.