Curled index finger

My baby is 3.5 months old and still sometimes keeps her hands in a fist. When she plays and is awake, I noticed that her fingers do straighten out except her index finger most of the time remains curled in. Anyone else’s babies do this?

When she’s sleeping or relaxed they are all straight. But idk if the curled in finger is going to affect her holding things or pointing etc in the future