Is the mom using any crazy diffusers or anything on a regular basis that could be aggravating her daughter's airways? Do they have pets?
I had this dayhome lady that refused to acknowledge that my daughter's allergies acted up at her place even though she had 3 cats and other weird stuff she used that she figured was good for the kids. Instead of telling me what was going on, she started using a diffuser to get scented oils (essential oils they were called) into the air, which really caused even more problems for my daughter. She started getting puffy eyes and a chronic cough. My daughter started getting chronic diarrhea after we dropped her off, and that is when the dayhome lady finally phoned us, to accuse us of not telling her that my daughter was sick. I took my daughter to the doctor (since she didn't have diarhhea before we dropped her off), and he said the diarrhea was caused by all the junk in the lady's home (cats, oils), not ours. The dayhome lady tried saying that we should stop giving our daughter milk at one year of age, and to start giving her protein powder instead. The doctor told us to pull our daughter out of the dayhome, and gave us a note to get our daughter transferred to a different dayhome. He said protien powder would cause too much of a burden to our daughter's kidneys.
Once we pulled my daughter all her symptoms stopped. She stopped getting diarrhea, she stopped getting puffy eyes, she stopped coughing. These altie lovers NEVER see that their idiocy causes most of the problems in their homes. It had to be the milk we were feeding my daughter. It was OUR fault that she had diarrhea. Well, my daughter is 7 now, and still drinks milk. We have since noted that she gets diarrhea when she is around cats for several hours. Her digestive tract gets irritated first, then her skin, eyes, etc. Weird, but true. The doctor confirmed this. Inflammation is a crazy thing with allergies. It affects many parts of the body.
The doctor said my daughter would have developed asthma if we hadn't pulled her from the dayhome.
Can your friend get legitimate allergy testing to see if there is something she can avoid? It just involves putting some allergens under the skin to see if a bump forms. I came up severely allergic to cats, somewhat allergic to dust, milk, eggs and dogs, but not allergic to chocolate (yay!), not allergic to grass, etc. I had a couple of environmental allergies, and a couple of food allergies. Avoiding the allergens did improve my breathing and skin. I no longer have eczema or huge build ups of phlegm.
Just wouldn't hurt to check what else might be aggravating the asthma in her own home.