How to make my little sister nicer?

Treat her how you wish to be treated and talk to her about how you feel about her attitude towards you. Ask her why she treats you the way she does and explain your dislike of her attitude. Ask her how she wants you to treat her and offer a deal. If this doesn't work then mabey she does not understand what she is doing or saying to make you feel that she isn't nice, try explaining what you dont like her doing and try to make sure she understands that she isn't being nice. Hopefully this helps Best wishes, Lilliy

Goodness, this is one that surely hits home. I've had a difficult sister for most of my life, but I can say that when she reached a certain age and started to mature, things became a lot easier. Unfortunately, you can't change your sister. We can't change people when they are unwilling to learn and change. All you can do is be beside her and guide her in the right direction with your own behaviour. If you're lucky, she might pick up on those subtly communications and start to questions her own behaviour. However, straight up telling her things won't always be the best direction. Hope this helped!