On the home stretch for fisting wife's pussy!

I just thought that I would share our progress and hope that we can get some positive feedback to help us on our fisting quest.

We have taken some pretty big strides towards our fisting goals lately and get so excited every time I think about it, now that she seems to be as keen as me to take my fist!
Our last effort saw her take me to my last knuckle on my thumb,which when you look at it ,is SO fucking close! She's balking at this last push and I'm not forcing myself in without her approval. But I'd love to hear back from any experienced fisters on here, should I go for that last clearing push and get it past that last barrier?
We've been very patient so far and would love to get some advice on how to proceed from here.

Very very close