I only have one sibling, so not much of a choice there.
I only have one sibling, so not much of a choice there.
Making her laugh will be a good start. William Goo has a good answer "helping," doing something together can be bonding.
Talk to her stare/glance a bit and then look away when she notices or hold it for 2 seconds then look away. Girls like attention and when they see you they decide that they might actually like you.