I have a 4 year old daughter and she's been "masturbating" since she was almost 3. She balls up a stuffed animal or a blanket and puts it between her legs, lays on her stomach, and goes to town. She's in daycare, and we were told by her 3 year old classroom teacher that this was going on, but it wasn't a "this needs to stop" it was more of a "hey your kid humps her bunny" and nothing else was ever said. She only does it at bedtime/naptime, but I want her to stop. I understand it's "normal" for children to do this, and, as much as I don't want to admit it, I started at the same age she did, and it became an addiction. I don't want to embarrass her, because my parents used to embarrass me to death.. they even took me to a psychiatrist to talk about it. I was never sexually abused as a child, and I know my daughter hasn't been, but I feel guilty because I did it the same way she did, at the same age, and I don't want her to continue and end up like me. She's about to start school and I don't want it to become an issue with her teachers like it did when I was in Kindergarten.
Any suggestions or advice?

If she only does it at nap time or sleep, there is no stuffed bunnies when she starts real school, just day care. And no naps in Kindergarten, at least in my area.

So tell her to stop, take bunny away if she does not.

You need to tell her that this is not appropriate to do in front of other people. If she wants to do this then she must do it in the privacy of her own bedroom and no where else.

You need to tell her that this is not appropriate to do in front of other people. If she wants to do this then she must do it in the privacy of her own bedroom and no where else.

She only does it in bed, but others have caught her doing it (her grandmother, her dad, and I). She shares a bed with her sister at my house, but has a separate bed at her dads, and my kids and I share a room, so she never has any privacy. She's learned not to care about that.

I just want her to stop before my parents find out and start traumatizing her like they did me and blame me for it.

Have you discussed this with her pediatrician?

Very normal. But like others said, make sure to teach her that it is only done PRIVATELY. And If your parents would do this, talk to them about it first. Put your foot down and make sure they know it is absolutely UNACCEPTABLE to talk to your daughter about it. And that YOU will be taking care of it. And if you are very concerned about your parents reaction, don't leave her alone with them.

And make sure she DOES have privacy. All kids need privacy. How old are your other children? Let her know that she is allowed to go into the bedroom and that you (and if she has older siblings) will knock before going in.

She has discovered something that probably gives her comfort. She hasn't sexualized the behavior, she's too young. Handle this behavior as you would any other behavior, with calmness, understanding and patience.
If you "demonize" it, she will not understand and will develop an obsession with it. This is probably why you did, you were humiliated at a very young age by your own parents. Keep in mind, how you react to her at THIS age, will affect how she views her own body and eventually, her own sexuality. Talk to her pediatrician about how to handle this as well. This is minor, in the grand scheme of things.