i noticed abit of redness around my anus my girl thinks its nothing and its normal
Stuff like this is caused by something, or a combination of things that is / are irritating the skin.
Anywhere in the Ano-Genital region is subject to particular conditions, such as warmth, sweat in combination with what is placed on the skin deliberately, such as soap and shower gel, and what else it contacts, such as underwear.
Common causes of problems can be a change of soap or something like a shower gel or other body wash you have not used before. Then there are things such as what your clothes are washed in, here most common causes are poor quality soap powder and fabric conditioner - again for these it is more likely due to the use of something you have not previously washed your clothes in that is causing the issue.
However, it is more likely a combination of the factors that I have mentioned - a skin irritant of which I have exampled, and the sweat and heat of the area in which the problem exists