.. I'm standing by my statement to see a doctor
however... for purely informational purposes...
I"m assuming that you don't have mammouth hands... and her hands are smaller than yours are... what if she inserts her fingers into herself - and if she's self conscious - she doesn't have to do it with you watching.. she can report back.. because I'm assuming that you are discussing this with her...
Tensing up could also be part of the problem - that she might be expecting it to hurt... and it is..
Basically - -is it anything inserted that causes pain?
(there's a thread or two on visiting a gyno-- if she wanted to pop by and read - it's honestly not that big a deal... having some of that info might make it less scarey... (and make you look like a really caring boyfriend