Sleep - a little longer - Please!!

How to get my 6 month old to sleep past 5am? That is the question. She sleeps pretty well - from around 8pm to 5am - 9 hours. But she cannot seem to sleep past 5 am - EVER! She gets up and has a bottle - then about 1 1/2 hours to 2 hours later she will go back down for about an hour nap. I wish she would sleep the extra hour in the morning (until 6am at least) then get up for a bottle and be up for a few hours longer. It makes mornings very difficult to get everyone up and going. On the days I work - she wants to take her hour nap when we have to leave and so we end up with a very cranky baby (as well as a very cranky mommy and whinny 2 year old sister to top it all off). I just wish there was a way to get her to sleep an extra hour longer in the morning. We've tried putting her to bed a little later but it does not seem to help. She has a full bottle right before she goes to bed so I'm at a loss for what to do. Any suggestions??