I think it's right to have stripped the mother of citizenship, yes. She is a member of ISIS and agrees with what they stand for, meaning she doesn't agree with what the UK stands for. Do we allow people like that back on British soil in the mindset that she is currently in? The fate of the child was down to the mother mainly, as the journo said, there was a lot she could've done before the baby was even born, but instead, being a true ISIS believer, she chose them over her child.
So in her instance, I think the UK has done the right thing. But that doesn't mean that I think any children should be left in a camp - but there is a real and difficult problem as to how to deal with this situation.