I mean, be primarily responsible for sibling(s) during the labour at a home birth, while dp supported me. Or would this annoy them because they seem themselves as direct supporters of women in labour (rather than indirectly).
I would imagine wanting one to take care of dd - bring her to me if she wanted me, explain things, then take her away if she wants to go and do something else or if she is being distracting. I would also want her to be a back up in case I had to transfer to hospital.