I don't have a five year old (yet) but I did do a course on sex education with kids that age.

First up, I think it is very normal and I don't think you need to discourage it but she needs to know when it is appropriate and when it is not.

We taught "public and private" as a way of talking about that - talk about her about "private" places like the shower, bath, toilet, her bedroom etc and then talk about "public" places like the park, kindy etc and then liken those places to places on her body. There are some places on our bodies that are public and it is okay to talk about it in public, show it off in public like our face, arms, legs etc and there are parts of our bodies that are private and we only do certain things in private. There is absolutely nothing wrong with what she is doing and she needs to know that but it is something we save to do in private.

The other part of that that we teach to kids this age is self protection - what is a good touch? what is a bad touch? how do they feel? A good touch is a touch that we want - so kisses and cuddles that we want. A bad touch is a touch that we don't want or touches that hurt - so being kicked or hit, but also kisses and cuddles that we don't want. I have been careful to make sure that my kids know that if they don't want to be touched at any time, even by us, that it is okay to say so.

Then the other part of self protection is No, Go, Tell. If someone touches us in a way that we don't like or makes us feel uncomfortable then it is okay to say "No", run away from the person and tell an adult that we trust. We get kids to hold up five fingers and name one person for each finger they could tell if they were being touched in a way that they didn't like (parents, teachers, police, grandparents, doctor etc).

I know the last part wasn't really related to your initial question, but the self protective behaviours go hand in hand with understanding ourselves and our bodies. There is a really good book by Family Planning Queensland called "Everybody's got a Bottom" that goes through all about our bodies, which behaviours are appropriate where and self protection. Our local library has a copy I borrowed for our kids and I really liked it so I will be buying a copy for us now.

Hope that helps as a very long winded reply to your question