Bulma was working in Capsule Corp Labs and decided it was time for a Break. Vegeta and Goku were training with Whis and Beerus, Trunks spent all his time going to School and getting into mischief with Goten. This left Bulma to take care of Bulla on her own, but she was used to being a Mother who did all the kid raising work. She did it with Trunks after all. She was getting a drink when she heard a noise from outside.