I have a Doberman who seems to always have the need to be touching me. Is this an issue, should I be worrying about it?

I purchased "Your Puppy 8 Weeks" DVD. Very informative. During our life time my 4 children and myself have had an assortment of dogs. I just purchased a Doberman puppy in June of this year. This is the first Doberman that we have ever owned. I have had German Shepherds, Labradors, Great Danes, Rotts, also little dogs. My question to you is that my Doberman has, (I call it respect for "my" space, we raise and train horses. This is a must with horses.) If I am walking, she is right there. On top of you. I know that I shouldn't do this but, I do. When she lays on the couch with me, she has to lay on top of like my leg or something. Is this an issue? My daughter owns her sister. Which she is also just like this. We have found out, that even when we are outside sitting on the grass, hay bales, it is a must to them to be "touching" you. Two sisters, in completely different house holds, they both have this characteristic. One is an house hold with small children and mine is just with myself and my teenage daughter. She does this to anyone, or should I say to myself and my teenage daughter. I call it "hormonal," wanting to "launch." Is this the case? I have never had this issue with any other dog that I have owned. All, which were allowed in the house and to sit on the couch with me.

Thank you also for being a gift to dog lovers and the dogs they own!

Thank you,
Julie