I have to say, I thought your sister may be unrepresented because something sounded "wrong". The first issue she'll have is jurisdiction. This is probably a High Court case. I cant say for sure.
If you have a defence drafted by a solicitor that's good. Unfortunately, there will not be anyone available in Court to assist you. I suggest you ask you solicitor to instruct local counsel. (or you could instruct local counsel on a direct access basis). It will be cheaper to send a junior barrister than have your solicitor attend.
Do not worry about her having a MF. They have no rights of audience and can only assist your sister with paperwork, but cant actually say anything.
Sounds to me like you have this pretty much in hand! It'll be a few weeks before you get a date but check back and let us know how you got on.