Let's be honest, this book doesn't make a darn bit of sense with what we later find out about Tasha's continuity or homeworld but I appreciate Jean Lorrah taking the time to flesh out the dystopian Mad Max hellscape that Denise Crosby never got to do any development of. I mean, you may argue that SA gangs have no place in Star Trek (and I'd agree with your argument) but it's fascinating to note that Gene Roddenberry was the guy who envisioned a Federation world withdrawing and degenerating to man's primitive and horrifying barbarism. Quark was right about humans and apparently the Father of Trekdom believed that it was only a few meals between your typical Hooman and a muggato.
I think one of the great authors here could easily fix most of the issues here. "New Paris" may have been the colonies original name before it was changed with independence (politics tends to do that) or it may have been its local name with Turkana IV being the official planetary name. Certainly, young uneducated waif Tasha Yar is not going to draw too much distinction as a little girl. Ishara Yar is a much bigger issue but I maintain that I actually think the Enterprise crew were right to be skeptical. If not of her being biologically Tasha's sister then how close they were since the Tasha we knew in the show was unlikely to have abandoned her 10 year old sister. Then again, continuity is fluid and sometimes you just have to say, "Yeah, that's no longer canon."
My headcanon for Ishara Yar is that she is biologically Tasha Yar's sister, or at least half-sister, and the two of them never met. The Coalition, however, encountered some traders that had encountered with the Federation and noted that the USS Enterprise had once had an officer named Tasha by sheer dumb luck--so they set up on making up a story about them being close as part of the con we know they pulled off.
If you wanted to make a whole novel about it, it was possibly a plot by Sela to screw with the ENTERPRISE and Ishara might even be someone she made in a lab somewhere before handing her over to the Coalition. Why? Maybe to involve them in a Prime Directive dispute or part of a larger plan that fizzled out. To make them feel guilty. I dunno, Sela has issues.
I have some issues with the book and that is the kind of "romance novel melodrama" that rubs me the wrong way. This needs to have the kind of asterisk that I feel I need to establish because I love romance novel melodrama and never want to feel like I'm criticizing a fellow author too harshly. I love melodrama, I live there. Still, "guy who looks like my current love interest who rescued me as a child that I later fell in love with as a consenting adult but was wrongly accused by a kangaroo court system then became a pirate/scoundrel mercenary/freedom fighter" is a bit much. Imagining Brent Spiner as a badass rogue is kind of hilarious, though, given all the statements Daryll Adin AKA Dare looks like Data, though.
My wife would LOVE this book, though, for that exact sort of storytelling, though, and I may have it be her first Star Trek novel. I feel like the villainess being a femme fatale dictator of her country (and tied to the orions) was a good twist even if I wondered how she ever thought the Federation would respond to a request to put down the local warlords positively. Not even the United States of the Eighties would be interested in that.
