Baby Bjorn Mini - how to straighten baby's position

[Hyggeandhugs]

I'm trying out the Baby Bjorn Mini for the third time and I just can't seem to keep baby straight, she's sort of slumping or curving to one side. Not sure if it's just because she's a very thin baby, or even if this is normal and okay. I can't work out if there's a particular adjustment I should be making and to what bit. Does anyone have any advice?