There's no reason to regret leveling both of them quite a bit although Awakening them both is a bit sketchy. A convenient thing about princesses is that unlike most other plats they don't require lighting 3 silver units on fire to reach max affection and the equivalent of 50cc70 stats. Thanks to her inherent tankiness Lilia in particular shines as a 2nd or 3rd string duelist that can help power you through the story maps and still make cameo appearances in maps like Golden Armor G even if you never bother to max her out.