Leaky nappies-Awkard vests

Hi

Please can somebody help, my 2 year old girl has had a bug since last night, and I am so frustrated, I have already in the past hour changed her 3 times, where the flap of her nappy has leaked and the flap of the vest is soaking wet, so i have had to remove all her clothing to take off her vest to change her again, shes drinking alot as she is dehydrated. Any suggestions