Every little girl wants to put on make-up and look beautiful like the older women, of course I would never put make-up on my sister when she was going out, but at home it's always a fun thing to do.
If you've got some old make-up, set up a little spot somewhere with a mirror, the make-up, some tissues and any thing else you need. Get your daughter/sister/cousin or whoever to sit down and then apply make-up to them. Blusher, lipstick, eye shadow, lip gloss, foundation, anything that they want. Then make sure you take lots of cute photos to share.
If you're great at doing hairstyles, grab a hairbrush and do some cute do's on your little sister. Take photos so that she can choose the one that she wants to have on a certain day. My little sister loves when I try new cute hairstyles on her. Her favourite is braids.
Get your sister or daughter to apply make-up to you and do up your hair. It's good practice for them to try it out on other girls so they can learn to do their own hair. My sister has been practicing doing ponytails on my hair ever since she was about 4, so now she can do her own hair for school and on the occasion I do her hair up really nice. We take photos together and we have a lot of fun, its a great bonding time.
Get out the nail polish and paint each others fingers and toe nails. My sister loves doing this, however she isn't allowed to have it on at school because it's a distraction and it can come off and get into food, and there is a little girl in her class that is actually allergic to nail polish. We chill out in the lounge room, go through all the nail polish colours and we paint each other's nails. My sister loves having multi-coloured nails, so I paint one finger yellow, then another green, then blue, then pink and so on. She is getting the hang of painting mine and it looks quite nice.
Girly movie night - my sister and I sometimes will get into our pajamas and then watch a bunch of girly films or cute Disney movies. We have a lot of junk food with us and we pig out and watch films. It's fun and great time to spend with each other.