I have a series of Ace Attorney drawings depicting events on significant
dates, usually holidays, which I mostly also tried to do in the year
they occur, based on the only year revealed in the games: 2001 for the
death of Gregory Edgeworth. From that, you can extrapolate the rest.
Thus you can also extrapolate the years in which Professor Layton events occur, based on the fact that the crossover is between Trials and Tribulations and the Magnifi Gramarye case on the Ace Attorney side, and Diabolical Box and Unwound Future on the Professor Layton side.
Thereby, we know that Katrielle is born this year, 2021, in April or May since she is a Taurus. It is very fitting that Taurus time is always mostly within the Easter season.