Perhaps the OB is just erring on the side of caution as rupturing could lead to a very sad outcome of all. My sister was booked in for a c section at 38 weeks because of risk of rupture with second pregnancy. Unfortunately this did in fact happen at 37 weeks - sadly resulting in the loss of her daughter and a hysterectomy for her. She lost 4 litres of blood and nearly her life and was on life support for two days after.

So although your SIL is wanting a VBAC it may not be the best and safest thing.

I hope she gets her longed for birth, complication free with a healthy bub.

Cheers Trea