I don't know, there is something in Adela that makes me want to doubt her actions. Since she said that everything was just a game. It's easy for someone to sacrifice some pawns  (or realize some of Martin's requests and try to befriend him) in order to achieve something greater in future. Holly and Adela don't appear to be very close, she doesn't even call her 'mother', at leat not too much from what I noticed. Martin certainly has a very strong willed mind, maybe is something both Holly and Adela desires a lot at the moment. It's so easy for most men or women to fall in temptation, with Holly/Adele's power this temptation looks so absurdly greater that is enough to make them even desire to lose humanity and live only to these carnal feelings (I can think of many people from ours giantess community). Others that don't apply to these feelings, certainly would lose their mind to fear, chaos and despair. I can think that only a very few people that would try to adapt and live this new life as best, happy and healthy as they could. I can't help but to picture Martin being a very valuable piece in their game and both of them are somehow fighting for him.