https://locusmag.com/2021/12/diana-g-gallagher-1946-2021/

Writer and artist Diana G. Gallagher, 75, died December 2, 2021 of chronic obstructive pulmonary disease. Gallagher wrote space opera The Alien Dark (1990), but was best known for her tie-in work for properties including Angel, Buffy the Vampire Slayer, Charmed, and Star Trek. She was active in fandom as an artist, winning a Best Fan Artist Hugo in 1989 (as Diana Gallagher Wu). She was also a prolific filk creator, winning Pegasus Awards in 1986 and ’94.

Born March 19, 1946 in Paterson NJ, she eventually settled in Florida. Gallagher was married four times; her third marriage was to author William F. Wu (divorced 1990), and her final to writer and fan Martin R. Burke, who predeceased her in 2011.

For more, see her entry in The Encyclopedia of Science Fiction.

(end)

https://en.wikipedia.org/wiki/Diana_G._Gallagher
(this has links to two interviews at the bottom)
https://www.fantasticfiction.com/g/diana-g-gallagher/
(book covers - this has five Buffy novels, though not all together)

https://www.goodreads.com/author/show/67119.Diana_G_Gallagher
(includes her photo - and, as so often happens, some lazy editor lists her birthday as being January 1st when it WASN'T)

From "Contemporary Authors":

....Gallagher was drawn to fiction writing by her interest in the “Star Wars” and “Star Trek” films. She has written “Star Trek” novels based on both the “Voyager” and the “Deep Space Nine” series, as well as Shadows, a tale based on the Smallville television show about the younger years of Superman. In Shadows, young Clark Kent becomes suspicious when a farmer he knows dies from unexplained causes. Other people begin dying mysteriously as well, and the strange malady seems to affect animals too. Clark and his friend Chloe investigate, but their progress is closely followed by the daughter of a scientist who is new in town and who may have ties to secret experiments. According to Kristine Huntley in Booklist, “The satisfying tale builds to an exciting climax that [Smallville] fans . . . definitely will want to read.”...

CAREER
Writer. Has also worked as a horseback-riding instructor, artist, and folk singer.

AWARDS
Hugo Award for best fan artist, 1988.

WRITINGS:

NOVELS

The Alien Dark, TSR, 1990.

(With husband, Martin R. Burke) The Chance Factor (“Star Trek: Voyager” series), Minstrel Books (New York, NY), 1997.

Invasion (“Journey of Alan Strange” series), Minstrel Books (New York, NY), 1999.

Shadows (“Smallville” series), Warner Books (New York, NY), 2003.

Spark and Burn, Simon Spotlight (New York, NY), 2005 .

“SECRET WORLD OF ALEX MACK” SERIES
Alex, You're Glowing!, Minstrel Books (New York, NY), 1995.

Bet You Can't!, Minstrel Books (New York, NY), 1995 .

Witch Hunt, Minstrel Books (New York, NY), 1995 .

Mistaken Identity, Minstrel Books (New York, NY), 1996.

Go for the Gold, Minstrel Books (New York, NY), 1996.

Poison in Paradise, Minstrel Books (New York, NY), 1996.

Zappy Holidays, Minstrel Books (New York, NY), 1996 .

Frozen Stiff, Minstrel Books (New York, NY), 1997 .

Milady Alex, Minstrel Books (New York, NY), 1997 .

New Year's Revolution, Minstrel Books (New York, NY), 1997.

Canine Caper, Minstrel Books (New York, NY), 1998 .

Gold Fever, Minstrel Books (New York, NY), 1998 .

Paradise Lost, Regained, Minstrel Books (New York, NY), 1998.

“STAR TREK: DEEP SPACE NINE” SERIES
Arcade, Minstrel Books (New York, NY), 1995 .

Honor Bound, Minstrel Books (New York, NY), 1997 .

“ARE YOU AFRAID OF THE DARK?” SERIES
The Tale of the Curious Cat, Minstrel Books (New York, NY), 1996.

The Tale of the Pulsating Gate, Minstrel Books (New York, NY), 1998.

“MYSTERY FILES OF SHELBY WOO” SERIES
Takeout Stakeout, Minstrel Books (New York, NY), 1997.

Cut and Run, Minstrel Books (New York, NY), 1998 .

“SABRINA THE TEENAGE WITCH” SERIES
Showdown at the Mall, Archway (New York, NY), 1997 .

Halloween Havoc, Archway (New York, NY), 1997 .

Lotsa Luck, Archway (New York, NY), 1998 .

Now You See Her, Now You Don't!, Archway (New York, NY), 1998 .

Shamrock Shenanigans, Archway (New York, NY), 1999.

Bridal Bedlam, Archway (New York, NY), 1999 .

Reality Check, Archway (New York, NY), 2000 .

Wake-up Call, Archway (New York, NY), 2001 .

From the Horse's Mouth, Archway (New York, NY), 2001 .

“BUFFY THE VAMPIRE SLAYER” SERIES
Obsidian Fate, Pocket Books (New York, NY), 1999 .

Prime Evil, Pocket Books (New York, NY), 2000 .

Doomsday Deck, Pocket Pulse (New York, NY), 2000 .

“SALEM'S TALES” SERIES; FOR YOUNG READERS
Dog Day Afternoon, Minstrel Books (New York, NY), 1999.

Worth a Shot, Minstrel Books (New York, NY), 2000 .

“FULL HOUSE: SISTERS” SERIES
(Under pseudonym Diana G. Burke) Will You Be My Valentine?, Parachute Press (New York, NY), 2000.

Substitute Sister, Parachute Press (New York, NY), 2000.

Matchmakers, Parachute Press (New York, NY), 2000 .

A Dog's Life, Parachute Press (New York, NY), 2001 .

“CHARMED” SERIES
Beware of What You Wish, Pocket Pulse (New York, NY), 2001.

Spirit of the Wolf, Pocket Pulse (New York, NY), 2002.

Dark Vengeance, Pocket Pulse (New York, NY), 2002 .

Of Mist and Stone, Pocket Pulse (New York, NY), 2003.

“TWO OF A KIND” SERIES
Santa Girls, Parachute Press (New York, NY), 2003 .

Prom Princess, Parachute Press (New York, NY), 2004 .