Its different in every state, i just read where she is working its illegal
Its forbidden everywhere.
The 'RED light activities' were put into the same category like huge Clubs, discotheques, festivals, big sport events, fairs - and this doesnt surprise if you think about the high number of men one prostitude has sex with each day.
Therefor, like all of them, prostution will be allowed just at the far end of everything else.
Sure, the longer the shutdown takes there will be more ladies or perhaps even Clubs which will offer prostition illigaly. And perhaps some regional governments will tolerate it if infections dont rise again.
But its still illigal - i am sorry.
And as i know its quite everywhere in Europe : Amsterdam, Italy, Spain, Belgium,...