Technically she is a married woman. That is just a fact. At some point she may be divorced, but she is not divorced today.
You can argue that we are all free to do whatever we want. You are legally allowed to sleep with anyone (of age) that you want to whether you are single, married or divorced. That doesn't make it right.
I don't understand the mentality that says it is OK to cheat on your husband if you are separated, or unhappy, or just want to.