Has she checked her due date with all the EDD website you can go onto now... Maybe introduce her to bellybelly and start her off with "how to work out your correct EDD" and follow on from there...and then quickly follow onto big vs small babies and induction and first time moms births...etc. Also informing her that labour can be long (and sometimes quick) so she has some knowledge and get her to talk to someone like Alan or other doula/private midwives...Once she is connected with other preg moms and new moms she may see she has plenty of option...
Also keep in mind that you do get some ladies who prefer the Dr route and whatever it may lead to but at least try to inform her but let her make her own choice at the end and then step back.
At least you can say you tried... and like my dad always says "every action has a reaction and one needs to accept responsibility for ones own actions and the consequences there of..."