Tell her to go for it, but of course even the best laid plans can change during labour.
Would she consider hiring a birthing pool and having a home birth? This is what I did as water births were not available at the hospital.
Even though I've had two home water births, I did not find the water to help with the pain. It did help with my mobility during labour, and possibly relaxed me which sped up the contractions. I have a couple of friends who really hated the water during labour for this reason.
I loved being in the water during my labour and found it very calming and relaxing especially during the first few hours of 'established labour'.I think it also helped with the pain until I was about 6cm dilated. After about 5 hours of being in the water I started to feel worn out with the contractions and decided to have some pethadine. At this point I wasn't allowed to stay in the water as it was their policy (due to drowsiness caused by the drug), which I was a bit disappointed about. I'm due again in March and would really like to give birth this time in the water as I think it's got the potential to be a great experience (well, as great a giving birth can be!).
Have given birth 4 times, had 2 in pool at hosp. 2005 and 2006 births in pool, 2008 and 2010 births I couldn't due to staff shortages.
Both waterbirths were good, nice and private, relaxed affairs, I sort of called the shots more with the WBs. I felt more in control. DH watched both WBs but couldn't watch bed births as they were too 'graphic'.