She's just a narcissist. Narcissists love their children only as an extension of themselves, so Lawrence gets all the love because he makes her feel good about herself, having inherited her looks and being a son of the Emperor and generally being authoritative. When the meek Artezia gets in her...
Holy shit I remember stumbling across the cover and synopsis for the LN version of this a long time ago, it certainly looked interesting! Isekai yuri ftw.
So....reviving people actually costs a ton of money, the cost goes up as they level, but the Church isn't allowed to charge them excessive fees either?