I feel that there are two aspects to this question:
We don't have any evidence in canon of what it would be like for the Borg Queen to be physically removed from the Collective (i.e. remove/disable her 'link' with the Collective). She is predominately made from technology with very limited biological structures left intact.
This is quite different from the case of Seven of Nine who was still primarily an organic being, with cybernetic implants. Conversely, the Borg Queen is more like a robot/android with biological implants! I expect that from a purely physical sense, the Borg Queen would probably be able to survive disconnected from the Borg; her technological body would probably survive. This doesn't take into consideration her link with the Collective though. When this link was severed for Seven of Nine, she suffered extreme pain and just about died of it. For the Borg Queen, who in a sense is the Borg (see the 'Mentally' section below), this connection may be more central to her functioning.
We can't really say whether it would be physically possible to free her from the Collective; theoretically it would be possible, but we can't overlook the possibility that severing her link to the Collective could be fatal.
(For the purposes of this section, I'm assuming that it is physically possible to liberate the Borg Queen from the Collective).
We know that the death of the Borg Queen doesn't mean the end for the Borg. In First Contact (set in 2373), the Borg Queen is destroyed, but we see the Borg Queen again in Voyager, beginning in 2375. This 'rebirth' of the (or a) Borg Queen shows that they can be replaced. Consequently, we can conclude that the Borg Queen could be replaced.
The Memory Alpha page on the Borg Queen provides us with some relevant information which I'll summarise here:
From this evidence, I think it's reasonable to conclude that, although she does exhibit traits of an individual unlike other Borg drones, this is rather deceptive. Her 'individuality' which she is showing is rather that she has taken on the identity of the Borg. She refers to herself as 'the Borg'; in her mind, she is the Borg, so when she refers to herself, she is referring to the Borg.
So, based on all of this, I conclude that the Borg Queen probably could be freed from the Collective. We know that the Borg can work without her and form their own collective (as seen in 'Unity') and even replace her (as seen in Voyager), meaning that she could be possibly removed from the Borg Collective.
However, I expect that a freed Borg Queen would have a rather different process of regaining her individuality than Seven did. The Borg Queen would already be familiar with certain traits of the individual, like emotions, which Seven had difficulty mastering. However, in Seven's case, one of the biggest difficulties was not having the Borg's thoughts in the background, having to listen just to her own thoughts. The Borg Queen would already be used to this; her thoughts command the collective. The difficulty for the Borg Queen here would be not having instant leadership; she would simply think of something and it would be done - when she became an individual she would have to learn to accept that others held power and she had to conform to certain customs and policies.
Another difference would be that the Borg Queen would need to redefine her identity, rather than develop a new one. Seven had no identity, whereas the Borg Queen already had one - that of the Borg Collective. The Borg Queen would need to create a new identity, but this would need to replace that which she already had (that of the Borg Collective).