My LO has just started making strange in the past two weeks - my brother came up to visit last week and tried to hold her a few times. Every time, she'd scream until he gave her back to me. And yesterday, she threw a wobbly when the teacher in our baby massage class came to have a word with her - I'm guessing she got too close or something. Part of me is delighted that she's clearly showing a preference for me and part of me is getting worried about what will happen when I head back to work etc. How long should I expect this to last for?