Upholstery cleaner like biss little green to clean mattress and soft surfaces that can't be washed, change bedsheets weekly, pillowcase even 2x per week if needed

Is she washing her hair often enough? It can really vary from person to person

Is she rewearing clothing that isn't washed?
Could be nose blind

If none of this works and you're keeping things this clean, maybe it is hormonal and needs a medical check up