When I spoke to the lady about this, she did say the brother and sister could stay together and the other would be okay on his/her own. My concern with this is, you've not only got the stress of them being fostered but then after 6 months, you will have to reintroduce the 3rd one back to the other two when they go back to their mum. I will see what she says, as even if as a last resort she decides to part with them, I don't want them to be split if it's unavoidable unless they all don't get on.