Is It Safe To Use A Nebulizer At Home For Allergic Asthma?

My niece is allergic-asthmatic since last 2-3 years She is 8 years. She gets v. Rare episodes only lasting for just a day or two. When we take her to the doctor, certain times she is given Duolin nebuliser, certain times not given nebuliser. With 1-2 nebulisers she becomes fine. I would like to know whether I can buy a nebuliser at home and give her nebulisation when she gets breathing difficulty, on my own. If so with Duolin? I m a physiotherapist, is it safe if I give here at home after getting an initial advice from her doctor reg.the dosage etc..?