What crimes has she actually committed? (serious question)

That would be dependent on the view of the government whenever she returns. To let her off scot free would encourage others. To make an example would make her a martyr and possibly invite retaliation.
I am glad it is not a question I have to answer. There is also the extensive "debriefing" required to establish what, if any, threat she poses.

As far as getting her back is concerned that could present problems.
Syria is still effectively partitioned and I have no idea how fluid those boundaries are. Having a river separating the government forces from the Kurds and Coalition? makes for a nice boundary on a map, but it covers many kilometres so how hard is it? She escaped from the last isis stronghold SE of Palmyra near the Iraq border to a camp in the NE,not too far from the Turkish border, in an area under Kurdish control. The map showing the men in black is somewhat out of date and their territory has shrunk.
But there are numerous caves they can disperse to in government controlled areas. They still pose a threat.
https://www.aljazeera.com/indepth/interactive/2015/05/syria-country-divided-150529144229467.html

https://www.businessinsider.com/syrian-secret-cave-hideouts-2015-3?r=US&IR=T