As Kajsa started this with the intention of going without drafting, on one bike, I'd probably suggest she carries on like that.
She can do it, and she would earn immense respect for sticking with it.
She should vehemently insist that GWR rescind their amendmend to the womens' rules, for attempts done under GWR rules only.
Keep the UMCA rules for those who want to set that record.
She should seek the support of all who care, who would be prepared to put their names to a petition, to respectfully request that Guinness do the only honourable thing and retain the rules which Kajsa planned hard for, and has worked hard to maintain.
You cannot reasonably change the rules for an event which has already begun, more so one which demands someone's invesment of a year of their life.
Be fair, Guinness, do the right thing, keep this a Guinness only record, based on your rules at the time the attempt was started, and do not change the rules to favour others or indeed to penalise others, once the year has passed.
Consistency is key.
Good luck Kajsa - ignore this if needs be, just the ramblings of an old git