Severe croup with breathing difficulties

Hi there I've never posted on a forum before but I'm desperate!

Our daughter is 3 1/2 had croup twice before, treated with dissolvable steroids and they worked almost instantly. This year has been a different story! Started out of the blue 6 days ago awful hacking and struggling with breath, prescribed a preventer inhaler and liquid steroids 4 tabs dissolved for 3 days.Saturday evening she looked slightly blue around the mouth took her to a&e and gave her a nebuliser andsent us home Early hours of this morning she was really struggling we did the usual cold air but to no avail straight to emergency where she was sick, we've been sent home again as they said no more treatment really any advice out there shall I continue with preventer inhaler?????

Thanks in advance