1) You specifically state "little" sister. I'm not here to bash on little girls. You won't state her age like a faggot so I'm going to assume a preteen. I personally didn't start actually showering properly until I was 14/15 and got into high school. I showered daily yea but I didn't do behind my ears. My feet. My junk. I would just do my chest and be in/out of the shower in 5 minutes. These days I usually take a 15-20 min shower as an adult and make sure to scrub everywhere. She is "little" (whatever that means) so I'm going to give her a pass on this
2) Diet makes up a whole lot of what you smell like. I can guarantee you she doesn't make her own food. She is a child and just fed what is given to her. Again, nothing to bash her about
3) If she is "little" then she has no concept of being smelly or maybe even good hygiene practices. Why don't you MAN THE FUCK UP and go into her room and offer to take a shower with her? Show her good things like properly washing her hair or armpits. How to floss her teeth and use mouth wash if her breath smells. Maybe she just started her period and doesn't notice how bad period blood smells/how she smells like iron. Maybe BE A GOOD FUCKING BROTHER and show her how to insert a tampon?
Holy fuck you are a waste of space OP i wish I was in your place so your sister could finally have a good fucking older brother that actually cares about her instead of shitting on her on an incel forum