It completely depends on her reasons for the transfer. Where do you both live? are there young children who would require childcare if STBX needed to travel?
My ex applied to a court 350+ miles for where he, myself and the children live. My solicitor said she was 99.9% certain it would be transferred but ex would not agree. The day before a transfer hearing was set/ barrister booked etc ex backed down at last minute and agreed to the transfer. (he knew he was not going to get his way!!)However being unfairly awkward only cost money!!. The case was transferred.