In the renaissance the church began to lose its power to the laic state so its laws also weren't absolute anymore, the state's law began to be the actual form of control of citizens. If I am not wrong, there were never formal laws against her behavior it was more a matter of moral and custom. Society wouldn't accept her to do what she did, she would be criticised and ostracised but it wasnt illegal. But a may be completely wrong. (￣∇￣")
I love reading manga comments. You get to see all kinds of discussions, from astrophysics to renaissance church laws ^^
Who dare to say that manga is not art! ლ(´ڡ`ლ)
Many women had jobs during the Renaissance. And in major cities in Italy (maybe besides Rome), women did some jobs that would be considered "mans work" in the other Western European countries. Sure, her case is a little different because art, even in Italy, was man's job. But she wouldn't be arrested for it. Just ostracize her. And her cutting her hair wouldn't result in in a trial for heresy either. Some women had short hair due to their jobs. Like how in chapter 10, some women were dying cloth, there were instances where women in France cut their hair in order for it not to get in the dye and result in dyed hair.
Historically, gender roles were very very strict to the point of there being 'moral laws' against dressing up as the opposite sex as the case with Joan d'Arc. The Renaissance did see a flourishing of personal expression that did not automatically require prostration before the church, but werent there sumptuory laws that would have jailed her as violating for cutting her hair so short, least of all brand her as a heretic for doing so?