I would not be too concerned with the baby coming early or
with the mom or baby's comfort. I'm going to assume the
baby won't come that early and that any discomfort, while
....um...uncomfortable, won't harm anyone.

My concern would be what happens in an emergency? Is
that water cold to the point of harm? Can mother use
the PDF's you have? Etc.

I think I'd try to get a quiet moment with just me and
the mom so that any influences from others that might
want her to go or stay are gone. Then explain calmly
your few small concerns and ask her if she's OK with
those. Let it be (mostly) her call.