What type of disposable diaper have you noticed your mom sensitive to? For example, have they been plastic backed diapers, diapers with a cloth like backing? A particular brand?
I have bad skin issues with the cheaper plastic backed diapers on the market (Wings, etc...) but the higher end diapers (Dry 24/7, Northshore Supreme, Wellness...) don't seem to bother me. I have problems with cheaper/less absorbent cloth like disposable diapers too. For me, it's a matter of how much padding in relation to how much absorbent polymer the diaper has, it seems. The thicker diapers with more padding in comparison to the polymer don't bother me, whereas the thinner ones with relatively little padding compared to the polymer, do. Does that make any sense?