Obsessed with Big Brother

So my 3 month old is completely obsessed with her 2 year old brother. She constantly rolls, wiggles and reaches towards him. She only really settles when she is near him, is touching him, or can see him. I only figured this out today when I couldn't settle her but she caught sight of her brother and instantly went quiet/smiley. He was out a few days ago to find a pumpkin for halloween and my daughter cried the whole time he was gone. She wouldn't nap and I could barely get her to take any milk.

Is this normal? My mum and my MIL said none of their kids were like this but they also agree that my daughter is obsessed with my son.

Photo of my son with his "perfect" pumpkin for attention.