My sister is coming to visit from the US and bringing her baby - the baby is three months old. Can anyone advise on whether I need to buy a baby bath? DSis mentioned bringing her folding bath but that seems daft when they will have so much luggage and I'm happy to get something. Is one kind better than another? Or is there a size guide somewhere online that would give me an idea? I haven't met the baby yet and don't have any of my own so struggle to picture how big a 3mo is.