Age on this show is tricky when they have the same actress playing both their younger and their present day selves with little distinction between the two. In reality, Victoria Smurfit is 41 and was asked to play a 20 year old. When the ink spilled on her and she became the Cruella we know now, she looked more her actual real age and less the 20 year old we met. It could be magic, or it could just be the actress getting back into her wheelhouse, which is to say portraying her character in the way she did everyday, which is more in line with her own age.
Also, we don’t know how long it was between the ink spill and her going to the EF–mostly because we have no idea when that happened or even how that happened. Rumple seems to know Cruella but they’ve never met for the first time on screen thus far. Either he went to her, or she came over not long after the ink spill.