I'm sure everything will be fine Basia. The breeding can go on quite a while can't it? But that is a good sign I think, especially in a first time mating as sometimes the male takes a few tries to 'get it right'.
I have never found separating them too much of a problem - but I always have a glove on one hand and a thick piece of card in case there is fighting. I also check the female is in season before attempting :
I bring my male towards the females cage and let them sniff each other. Often that results in the female doing a swift scent marking around the cage before standing. This worked really well when we had wire cages, though I'm not sure that it will work with the Gabbers, so I will probably be trying your idea of handling Holly for future matings.
Fingers crossed for lots (though not too many
) lovely babies in 15 days time!
Good Luck