Hi Pete, so sorry to hear about this, sounds excruciating! Please give Debbie my best.
Not sure how much I can help, as my own search for the 'perfect' saddle had to do with pain in altogether different areas.
@vickster is obviously able to speak from experience and the points she has raised will be worth considering.
My take on it (without knowing the specifics of Debbie's situation) is that the short term plan is to wait til the current inflammation has subsided while the doctors see if they can identify the cause and what sorts of aggravating factors Debbie should avoid. Assuming she's eventually cleared to cycle, she may need to explore changing her position and/or saddle on her current bike, and (recommended) have a bike fit (preferably with an experienced physiotherapist - I can recommend someone very good in London if needed) in case she needs to make more significant changes -- maybe even get a new/different bike?!!
Meanwhile, I've had a little dig around the Team Estrogen women's cycling forum -- US based but quite a few UK members too. I don't know how helpful these might be but they may give Debbie some ideas on how to explore dealing with this when she's ready to get back on a bike.
http://forums.teamestrogen.com/showthread.php?t=41470
http://forums.teamestrogen.com/showthread.php?t=46330
http://forums.teamestrogen.com/showthread.php?t=42149
I'll just say, anything "KnottedYet" posts in these threads bears serious consideration -- she's a physiotherapist and one super wise woman. And "Muirren" is the forum's saddle expert.
All the best,
Rebecca