Maya is a 4 year old girl with suspected Asthma. She has been well controlled on low dose paediatric inhaled corticosteroid (ICS) inhaler for several months but dad is concerned she has started to have night time symptoms again for the last few weeks despite regular compliance with the ICS inhaler using a spacer device. You check inhaler technique with the spacer which is good and take a thorough history to rule out infection and any other potential triggers. Her observations and respiratory exam are stable today.
What is the single most appropriate next step in her management?