We know a lot more about the causes of asthma now and you might want to read this medical paper on the microbiome role in asthma
www.ncbi.nlm.nih.gov/pmc/articles/PMC6337651/ and this one www.ncbi.nlm.nih.gov/pmc/articles/PMC5707699/ and there are so many more.
I would suggest you read Dr. Erica Sonnenburg The Good gut book
( she has also done several interventions at conferences which you can find on YouTube such as this one) and then a deep and honest look at your child's diet and try to swap any processed / refined food for a natural one, in order to increase fibre intake.
You need to try to take control of asthma in its earliest stage because an asthma attack is one of the most frightening thing to experience. Watching my son unable to breath sent me into the deepest fear I didn't even know existed.
Fixing your DD's gut will regulate her immune system and help control these overreactions such as asthma and eczema in addition of course of using a preventer and having a Ventolin in the house (and in the car, school bag, swimming bag, every single one of my my handbags, .... I had ventolin everywhere for a while) .
And attacks can occur outside as well. One of the worst my son had was when we were walking on the beach in Manly. Luckily the lifeguards intervened very quickly and the ambulance arrived in a matter of minutes . Without them, my son would have died that afternoon.
Preventers, inhalers, allergy medicines are a patch on the symptoms. You need to work upstream, and introduce a lot of bacteria with fermented foods (yoghurt, kefir but also miso, sauerkraut, ..) and a lot of vegetables, prebiotics and also remove food that makes bad bacteria thrive, so most foods kids love, processed and industrial food made with refined grains, processed oils and so on. Anything wrapped basically.
While you do your research (go on pubmed, not google) , buy a ventolin and a spacer, because you never know when it will escalate .
Of course , @Zoink talk to your doctor first, because if your DD has asthma symptoms more than twice per month, she needs a preventer asthma.org.au/about-asthma/medicines-and-devices/preventers/ but you don't want to be long term (years) on them, as long term side effects are quite serious, from osteoporosis to cataract as adult and behaviour problems and stunt growth as children.
My son is now a teenager and absolutely fine. No need of preventer or reliever (but when we go on a long flight, I have a ventolin in my handbag, and will probably always have it for as long as he travels with us).