I can see a very real risk here. It seems that so far 100 UK residents have gone down the path to Securitas. In a very small number of cases, relatives and assistants have been questioned on their return. No action has been taken. One might read this as indication that the Justice department has turned a blind eye to what is happening. My amateur reading of the law suggests that charges could have been brought.
By demanding some form of judicial review, the woman runs the risk that some jobsworth will say to her returning husband "Your wife went to great trouble to check this out. She lost. You went ahead. That makes you a criminal" Her wish for clarification could rebound on all others seeking suicide. An example surely of the adage 'let sleeping dogs lie'?
I do have another bee in my bonnet. I do not know what form of wedding service they went through; mine said that I would protect my wife in all sorts of conditions. Were I this woman's husband I would be very firm with her. If suicide is what she wants - and it is not that decision she seeks to test - then I would do all in my power to see she gets that dignified end. It is not as if there is a lack of options to determine one's life right here in UK. I assume she has painkilling medication - save it up. There are any number of ways she could choose.
Doubtless, if anyone does read this, there will be some who hold that suicide is wrong. I respect that opinion. I do not hold to it. My suggestion would be to suggest that the deniers wait until their life is unbearable to them with no relief in view. Come back then and tell me about suicide being wrong.