I had bronchiolitis (or somesuch!) as a child (about 6 weeks) almost died, ended up in hospital etc, etc...(no one would take my mum seriously) but because of that I ended up being athsmatic (also with a heart murmur) was in and out of hospital until I was 5-6 years old, then my heart murmur closed over and I "grew out" of being asthmatic.

My neice was constantly getting sick, wheezing etc...her mum took her to sooo many docs, had so many courses of anti biotics etc,told it was allergies, put on claratyne for months, then FINALLY when she was 7 yrs old (this all started around age 3) a doc diagnosed asthma, suddenly she was a different child! now she is 15 and has "grown out" of it too.

Also my brother, quite badly asthmatic for a number of years, in winter mum always had the ventilator ready to go, I remember lots of late night trips to emergency too...anyway he also "grew out" of it around 12 years of age.

not much help for you but just wanted to let you know a few of my own anecdotes!
I'm sure Miss B has being giving you a bit of a fright, but with the right management and an action plan (not to mention the fact that you already know so much medically etc) I'm sure all will be well.
Big hugs gorgeousxoxox