M.R.
Yes, I would say this is very normal. She just sees you doing more things for the younger one. I went through the same thing when my daughter was 4 and my son was 2. Now they are more even being 6 and 4. She would ask me for something in a whiney voice, I would just tell her to ask in a normal voice so I could understand her. She eventually got out of the habit when she realized I wasn't going to comply when she whined. We also made her or her brother go in their room if they needed to cry. They got out of that real fast because all they just wanted was to cry iand throw a fit in front of us.