Bit of a random question. I've been sorting out a lot of my children's old clothes ready to put in a nearly new sale in April. I had put aside my son's old 'big boy vests' as these can be passed on to my daughter. I just had a thought though as to whether they would be suitable under her clothes. Are 'big girl' vests any different to those of boys or is it just a marketing thing designed to get us to buy two lots of the same thing because they are advertised for a single gender?