My daughter is living in a 1980 mobile home with mold in walls and ceiling and is symptomatic for 6 months with upper respiratory/nasal problems. Can a person replace walls, ceilings, and roof and rid place of mold and safely live in home.

Yes it could be done but it may cost more than the home is worth. The interior wall material, insulation and likely exterior needs to be removed and/or cleaned with a mildewcide, flooring too.

I hate to say it but Ive been there before with customers. 9 of 10 its cheaper to replace the Home.

Its an 80s home and lived it time.

Thake caution if you do replace it. Check with the local codes on placing another mobile home on that lot. Seen people yank off the old and not grandfathered it. Once a lot has NO structure it can easily fall under the new if any restrictions of lot size and new zoning laws..

As long as every porous and organic surface is removed and discarded and the place is treated with fungicide, According to the Center for Disease Control there is no way to effectively remove mold from porous and organic surfaces.
I am afraid however, that this process might, as others here said, cost more than the home is worth.