she can have the breathing treatment 4 times a day and believe me you will notice a difference and if you don't within 3-4 days I would take her back for another xray. sometimes pneumonia doesn't show up for a few days.
All 3 of my kids have had to use the nebulizer at some time with wheezing. 1st had Bronchialitis which was diagnosed as Asthma as he got older but his breathing problems started at 3 months of age and they didn't give us a nebulizer until he was 8 years old so it was really annoying that I had to take him in every few days for a treatment when it was really bad and usually every 2 weeks for a treatment when he was just coughing. I really like the nebulizer better than using inhalers and so do my kids. Even though inhalers are fast acting they make them feel whoozy and the nebulizer takes a lot longer but doesn't make them feel drugged afterwards. My oldest has had to take strong steroid inhalers before and really didn't like those when he was 3 or 4 years old.
It could be some allergy triggering this and if you have a lot of carpet in your house don't let her sleep on the floor as carpet floors hold a lot of dust. Also if you recently got a new pet it could be a pet allergy.
Another thing that helps is the steamy bathroom after someone takes a shower. Take your baby in the bathroom and let her breath the steam.
A cold mist humidifier in her room. The heat ones actually set it in deeper so you want to use a cool mist one.
Check your windows for mold. Aluminum windows tend to get more mold when there is a lot of condensation which happens more in the winter.
It is a bit scarry but hopefully hers is seasonal and not a constant cough like my son had from 3 months until he was almost 2 when we actually moved to another state and his breathing got a lot better. We lived in California when he was born and his breathing got better when we moved to Washington State. Then we moved to Missouri and TN and his breathing problems were more in the winter and early spring. We also lived in Georgia where all 3 of the kids had breathing problems A LOT which is when we got the nebulizer to be used for all 3 of them. Now we are back in Missouri and our oldest 2 haven't had any problems for several years and youngest seems to need the nebulizer in the fall months but it does help a lot as he will use it for about a week and not need it anymore for a while. Basically when he starts coughing a lot he starts using it and within a few days you can tell a difference in his cough not being constant.
If you are burning wood for heat. STOP because that is probably what is causing it. We tried to burn wood one winter and our son was so bad and wheezing and barking like a seal when he coughed.. It was horrible and the doctor was having a hard time figuring out the trigger because he was totally fine then it hit suddenly and was taking him to the doctor for a checkup every week with the doc calling often to see how he was doing. Well one visit I asked him if he thought burning wood was healthy and he said that is very unhealthy and to stop immediately. Well within 2 days our son stopped wheezing and barking like a seal and got so much better. We then bought ceramic heaters for each room and never burnt wood again. In fact that summer we had a new heat pump put in our house so we didn't have that issue the next winter at all.
Now when he goes on campouts I know he is going to be around a campfire and he tends to start coughing but you can't keep a boy away from the fun of a bon-fire so he just knows he will have to deal with the coughing for about a week after the fun. I make sure he packs an inhaler just in case of an asthma attack but so far he hasn't needed to use it when he is on trips.
also don't use cough suppressants for medication. You want her coughing the stuff up and suppressants keep it from coming up and trap all the junk in and could go to the lungs.
you can use benedryl for her runny nose but wouldn't use cough meds.
I also noticed that when my kids were wheezing bad and decided to take them to the ER that getting outside in the cold from the car to the hospital they wouldn't be wheezing at all by the time we got them to the hospital and of course feel like an idiot because they can't find anything wrong and wonder why you are in the ER. That happened so many times sometimes we would get to the hospital and notice they quit wheezing and went back home so sometimes getting out in the cold air for a minute helps.
Try to vacuum everyday and keep dust down.