The truly interesting thing is how she arrives at this conclusion. For her, it's not a question of whether prostitution in itself is good or bad. This simply isn't part of the process of moral reasoning. What matters for her is the question of "agency". If a women has made an uncoerced choice to become a prostitute, then prostitution must be approved (as long as it doesn't impact on the "freedom" of the wider community).
So the debate is framed oddly around a single question: can women make an uncoerced choice to become a prostitute? Dr Cannold chides those who believe that the answer is always no, as this denies women the possibility of "agency":
most offensive is the way in which the argument itself victimises sex-sellers by denying their experience and stripping them of their agency
What is needed instead is:
A position where sex-sellers are moral agents worthy of respect
So how does Dr Cannold then justify restricting the "agency" of those women who prefer to work the streets? She argues first that street work impacts on the wider community:
when the consequences of the selling choice restricts the capacity of the fellow citizens to exercise their freedoms, the state is obligated to restrict their activity
Second, street prostitutes are coerced in their choices:
A focus on autonomous choice also justifies state intervention where sex workers lack the capacity - because they are too young, mentally ill, sexually or physically abused or drug addicted, to make choices about selling sex.
So we get this conclusion:
This is why allowing brothels to operate in a regulated fashion is a good idea, but street sex work can never be tolerated. Not just because a disproportionate number of street prostitutes are too young, too drug-addicted ... to make an autonomous choice to sell themselves, but because the cost to the community of their behaviour, even if theirs is a choice worthy of the name, is far too high.
Dr Cannold is basing her approach on liberal autonomy theory, which is the idea that the overriding good is our status as self-determining agents.
The theory doesn't exactly work in a "clear and distinct" way. Dr Cannold begins by criticising those who believe that prostitutes are coerced in their choices. She claims that this doesn't respect agency and is obnoxiously paternalistic and an imposition of one person's view on another.
However, she herself then uses the "coerced choices" argument to declare street prostitution to be intolerable. Furthermore, she tells us that in order to make prostitution in general uncoerced a community would have to offer:
sex-sellers opportunities to exit, such as income support, places in drug rehabilitation programs and police intervention in violent relationships at regular intervals at their 'workplaces' and each time they have contact with the law.
Then there's this sentence:
Autonomous adult women have a right to sell provided they go about it in ways that don't unfairly burden the community of which they are a part, though as a community we have a positive obligation to ensure that at every stage of what is a potentially violent, exploitative and coercive game, a woman's freedom to say "no" is protected.
So the community is obligated to provide a burdensome protection to prostitutes' agency, even though prostitutes are obligated not to be a burden to the community, and even though prostitution has been morally justified on the basis that it is an uncoerced choice.
These, though, are minor criticisms. The real problem is that Dr Cannold assumes liberal autonomy theory to be true. In effect, the most important parts of her argument remain unstated and unexamined.