Thanks for the chapter!
Seems kind of odd the princess is a fire user with blue hair. Usually the hair matches the element the user is most proficient in. Then again could be is a lot better with ice/water spells, just hasn't learned any strong ones yet due to preconception that fire is strongest attack magic. I hope she is learning other spells than just fire attack magic. Looks like next talent has appeared.
@Shadowii There is no mother, the twins simply popped into existence. Seriously though no idea. If there's a LN it might have more details but until MC talks about her your guess is as good as mine. Might be a recluse or handling household books in an office almost all the time. Doesn't seem like she's shown up since MC was born in chapter 1 but definitely alive since twins were born.