Brian, I do hope you wife will secure the needed B1 English Language and that the ILR application can be submitted.

You wife's current spouse visa expires on 16 August 2014 which is a Saturday....so that means she'll need to post it on 15 August latest. It's tight I know but if that's the timing then not much to be done about that.

I'd suggest having with chat with her ESOL course tutor to explain the situation and setting out a plan of when and how your wife could arrange to receive her certificate.
If that plan doesn't sound like it's going to happen then she's no choice but to apply for extension of leave on FLR(M).
That'll give up to 2 years extension but will take out all the pressures.
Your wife will be eligible to apply for ILR at any time after she gets her B1 no need to wait for the full 2 years.

Good luck Brian, keep us updated.