There is something innately soothing about the Tonstix story so far. Start-ups are hard to get off the ground – LinkedIn is littered with the dormant profiles of good ideas that ran off the end of the runway. Manufacturing start-ups are harder still. Successful manufacturing start-ups led by first-time, female founders are the rarest of the rare, so finding one that seems to be thriving is a balm.Sinéad Crowther and Denise Lauaki, co-founders of Soothing Solutions, have nailed the playbook moves since founding the company in 2017. They met on the New Frontiers programme, found a suitable VC, ticked the…