And can anyone shed some light on the bea/elly/mother relationship?
I assumed elly is the older sister. Is her father this Lars chap? Or is Beas father Lars?
Their mum said Lars went back to his wife. So is Bea Lars & Ulrika's child or Lars and Susan's sister's (I forget her name)?
Im confused over the order of relationships and children!
Is it:
SS (Susan's sister) and STBXH have Elly
Meanwhile Lars & Ulrika are together
When Elly is a couple of years old SS & Lars get together and have Bea and stay together until she's a teenager?
Then Lars goes back to his wife after like 15 years or something? 
And Bea's a reminder so SS sends her away.. And in this middle class family no one calls each other/visits/contacts or anything for however many years she's on the streets for to notice she's not living with either parent?
The timings/orders don't make sense. So then I thought maybe Ulrika and Lars are Beas parents? Kind of makes more sense, except (a) she calls SS mum (b) SS said Lars went back to his wife, which suggests elly isn't his daughter. In which case elly and bea are only step sisters and not even half sisters (but everyone keeps saying how they're identical).
Arrgh. Has anyone else worked it out?