Oh bless her poor thing. Is she rear facing or forward facing, how big/old is she?
There is only the one recline position for rear facing. It doesn't have as much leg room rear facing as some other RF seats.
You should be able to adjust the harness height and the position of the head support.
Depending on which version of the All in All you have, some of them the harness adjustment is done by unhooking the harness from the metal yoke at the back of the seat, finding the right holes in the seat shell and rethreading it on at the correct height, in others you move the headrest up and down and this adjusts the harness. I'm afraid I don't know offhand how to change the headrest height, but normally there is either a button or a ring pull type thing on the top of the head support or occasionally a button underneath it which you have to feel through the fabric.
The headrest should be above her shoulders, as close as touching is OK, not too high above though. No more than a finger or two between the shoulders and bottom of headrest. A harness should come out of the seat level with the shoulders, if you're between slots, it's OK for it to be slightly above for forwards facing or slightly below for rearwards facing.
If you send an email to Cosatto they should send you a copy of the manual.