Iis it normal that i've been masturbating for as long as i can remember?

I'm 24 and female.

I've never been sexually abused as a child. I didn't even know what sex was exactly, until an embarrassingly late age (around 10, I think). But when I was a very small kid my mum used to rock me back and forth before going to sleep. And I remember quite clearly that one night she refused to do it anymore, so I started rocking myself - moving my body through my hips and legs. I'm pretty sure that's how it started... But I don't remember the precise moment when I first masturbated. I just know that by age 4 I was already doing it. And I know about that age because it was the first time I got caught and yelled at for it... I think I got caught once or twice more afterwards and then I learned to hide it.

I didn't (and still don't) do it like most women do, on their back and doing circling motions with their hands. I would instead sit on my stomach, with both my arms underneath me. My legs would grip my hands tightly between them. One hand would be pressing my private parts with the thumb-side, and the other would be adding more pressure, by pushing the side of the hand deeper. Then I would keep adding pressure and move back and forth until I reached orgasm. I never inserted anything inside.

I had no idea what I was doing. I just knew it felt good, so I kept doing it all through my childhood and teen years. Of course I never told anyone this before because I know they would judge.