The Internet Archive has copies of the University of California "Southern Campus" (the yearbook for UCLA) for the years during which Leslyn was a student (1923-1926) available for download. Highlights:
1923: Leslyn was in the Manuscript club (with a picture on p. 233) and in Le Cercle Francais.
1924: She participated in the "Spring Festival" playing the part of Pan, was in the Manuscript Club, and in Delta Tau Mu (a dramatic and music society)
1925: On the staff of "The Grizzly" (campus newspaper), wrote for and played in the "Press Club Vodevil of 1925", was in the Kaps and Balls dramatic club (picture page 357), again in Delta Tau Mu (pic p. 373), and the Manuscript Club.
1926: Acted in "L'Aiglon", was again in the Press Club Vode (played in, and asst director), Delta Tau Mu (pic p. 326), Kaps and Balls (pic p. 328), Manuscript Club, and her senior picture and profile were on p. 53 (in which it says she participated in productions of Agamemnon (1), Oedipus (2), Antigone (3), and Alcestis (4), in addition to L'Aiglon; and that she was on the staff of the Grizzly all four years).

In Robert James’ article, “Regarding Leslyn,” he mentions that Ralph Bunch attended UCLA at the same time, but there is no indication that they ran in the same circles. A few of Leslyn’s classmates did go on to some degree of fame, however.

Agnes de Mille acted in several of the plays mentioned above. She was the niece of Cecil B. de Mille, and went on to have a moderately successful Broadway career:

Myra Kinch appeared in the 1924 Spring Festival alongside Leslyn. She went on to have a career in dance:

Bruce Russell was an artist on “The Grizzly” at the same time Leslyn wrote for it. After UCLA, he became a staff artist for the LA Times and won a Pulitzer Prize for editorial cartooning in 1946:
and

James’ article says “Leslyn claimed to have taken part in putting on a production in 1923 of _Laugh, Clown, Laugh_ with Lionel Barrymore, but there is no proof of this . . .”. What little I have found about this makes me think she was possibly confused on dates, or exaggerating. Barrymore opened in "Laugh, Clown, Laugh" on Broadway at the Belasco Theater on 11/28/1923, and it played through March 1924 (having undergone “tryout” performances in Rochester on 10/15, and Chicago 10/29 -11/24, and probably a couple of other places and dates). It then played in Washington DC for a week. Barrymore spent the summer of 1924 in Europe, and returned for a run in Boston in the fall of 1924 with the play. At any rate, as near as I can tell, neither Barrymore nor the play “Laugh Clown Laugh” were on stage in Los Angeles in 1923.

The first evidence of a production of ”Laugh, Clown, Laugh” in LA that I can find was in an Jul 1925 LA Times article about “the Potboilers”, a “little theater” group that planned the first presentation of the play outside of the Belasco chain (but I can find no evidence that the production actually occurred).

Barrymore was at the Playhouse (not the Pasadena Playhouse, where Leslyn performed) in Mar 1926 in “The Copperhead”. He did do a run of “Laugh Clown Laugh” at the Belasco in LA, starting 11/28/1927. The LA Times article about the play that ran on 11/27 was illustrated by Bruce Russell, mentioned above.

It’s possible that Leslyn worked in a backstage role or as an extra in the 1927 run of LCL in LA, or elsewhere on its swing through the west coast (including Reno, San Francisco, LA, Santa Barbara), and confused the dates with the 1923 premiere. Or maybe the 1925 Potboiler production was in fact produced (but not mentioned in the LA Times), and she was in it (this seems more her speed – the 1927 run was a touring Broadway company, and it doesn’t really seem like Leslyn had the “chops” to participate in an acting capacity with such a group). Or perhaps, somehow through her association with the Pasadena Playhouse that year, she managed to meet Barrymore at a backstage party or some other event.

At anyrate, I can't find any indication that she ever was on stage with Barrymore, and that if she did know him, it wasn't because of a 1923 production of the play.

I've been wondering to what extent the Journal would continue, given the problems with the Society (doesn't/didn't it subsidize the Journal?), your own time constraints with the biography and the VE, and Gifford's stated goals for the Nexus that seem to include a role that the Journal has formerly enjoyed.

I'd love to continue the research above with a visit to the UCLA library. Surely the archives of the Grizzly exist somewhere on campus for those years. It'd be neat to find an article or twenty with Leslyn's byline, and read the coverage of the plays she was in. I assume Robert James was not able to do so when he wrote "Regarding Leslyn". Perhaps someday they'll be digitized and I can search them from Huntsville -- many college newspapers are doing so.

Excellent work, Bill!

And as for the Grizzly, I was unaware of its existence until now. All I know is that the official records of the school were all put on computer, then the originals were locked into deep storage.

I would assume you are correct about the library (one of them, anyways), having archived copies of that!

And as for the HS and the HJ, there is zero financial connection that I am aware of....

Sphere was one of the ones I couldn't access, despite repeated attempts -- the Hubbards have some more poetry too. My divorce hit in the middle of all that research, and I'm afraid I haven't gotten back to it...

I live in LA....I'll try and contact UCLA and see what they have on file for the Grizzly

Actually, it's not up to them -- the words are the property of Leslyn's heirs, who have, in the past, granted blanket permission to use her words.

Yeah, but the archivist doesn't have an iron-clad, lawsuit-proof waiver in writing from the heirs (and wouldn't know for sure who the legal heirs are in any case -- is it Colin? Ian? someone else? a joint combination of the above? Someone on Jules' side of the family? Did she die intestate?), so they embargo it. Pretty standard procedure at many archives, I believe. "Orphaned" works are a good reason to reform copyright laws.

We can get that permission, I think...but if you have copies, it doesn't really matter. The words are copyrighted to Leslyn's heirs.

From the Corona CA Daily Independent, 6/16/1921 p 2.

MacDonald Family Moving to Hollywood

Mr. and Mrs. Colin MacDonald and two daughters Leslyn and Keith, leave Saturday for Hollywood where they will make their future home. Mr. MacDonald is connected with the English auditing firm of Price-Waterhous in Los Angeles where he has been since January first.

The MacDonald family came to Corona from Riverside two years ago where Mr. MacDonald was employed as chief clerk and auditor in F. A. Miller's Mission Inn. While in Corona Mr. MacDonald was connected with the United Chemical Works as accountant.

The family during their residence here have made many friends who will be sorry to learn that they are permanently leaving this city. Miss Leslyn MacDonald is a member of this year's senior class at C.H.S. and was one of the most popular members of the class, her ability as an elocutionist, a dancer and a singer having won her many friends. The family address in Hollywood will be 6344 Primrose avenue.