Thanks everyone - if I take the stroller she will nap OK. We seem to be going through one of those I can only nap for 30mins fads at the moment and don't even think about making me sleep when I am out!
I hadn't heard of the pikkolo either it was recommended by someone I met at a baby group. I said I was dreading when Lara outgrew the baby bjorn as she LOVES it soooooo much and she said I should look at the pikkolo as it's the only one she knew of that still offers the facing out option.
Here's a link for info - should last until around 2 years old or so!
http://catbirdbaby.com/index.php/pikkolo-info/It's a little more expensive than I would like to spend, but can you really put a price on a high needs baby's happiness ;-)