I think it's even commendable to marry them.
Here is what I found :
"..They can marry afterwards just fine. The Prophet (saw), for example, married almost exclusively divorced or widowed women, who were also looked down upon. With some Qiyas (analogy), we can then see that marrying those women who have been raped would not be something looked down upon, but that should be honoured or upheld..."
"... there are no conditions that I know of that would apply in the case of the woman you had described, except that she would have to observe iddah, according to one opinion (but not according to the Malikis)..."
"...There are hadiths pertaining to the marriage of devirginized women who have previously committed adultry and that marrying them for their sutra yields a great reward..."