Trigger & Friends contains six stories, purportedly all dealing with Trigger and people associated with her (Trigger herself only appears in 3 stories, though is only a main character in Legacy). It's unfortunately quite uneven, with some of Schmitz's less attractive tendencies on full display with awkward info-dumping. "Harvest Time" and "Aura of Immortality" were interesting at least, and the included novel Legacy follows up on the scientific discovery from "Harvest Time," though was ultimate unsuccessful for me.
I have one big complaint, however, and that is Eric Flint & Guy Gordon's rewriting/reediting of Schmitz's published works, most prominent in this volume. The story "Forget It" is a rewrite by Gordon of the original story "Planet of Forgetting," prompted solely by Flint's wish that there was another story with Quillan (also in "Lion Loose"). The rewrite changes a bunch of elements to make it fit into the Hub setting that all the Telzey and Trigger stories are written in, and also cuts off the final two pages of the original story (available in the February 1965 issue of Galaxy on the Internet Archive). Flint acknowledges that it's "impure" of him to have included that, and I'd go so far as to say unethical, because guess what, if Schmitz had wanted that story to be a Quillan story, he would've written that. The other major reediting that was done was Flint's extensive structural edits of Legacy to remove what he considered pointless information that Schmitz included in early chapters (and removing silly things like mentions of cigarette smoking). Flint defends his actions in the Afterword and a commentary article by saying that he's only making the story better and that he's working for a general audience and not a scholarly one, but I think that kind of major change is not great, because he's creating his own vision of what he thinks Schmitz should have done. I'm pretty sure Flint would reject people doing that with his works, now that he's dead. Also, what's so funny about all this, is that Legacy is STILL boring as hell, and whether or not it's the original version (available on Project Gutenberg) or Flint's version, it's still not a good story.