In the 1890's Pinero wrote a play called 'Trelawny of the Wells'.  The
heroine was a juvenile theatrical lead named Rose Trelawny.
Was the character of 'Miss Rose' based on a real actress?  If so, is
any information as to her dates, biography, available?
Thank you for your consideration.

Arthur Wing Pinero (1855-1934) wrote 'Trelawny of the Wells' in the
late 1890s, looking back at the 1860s when plays made no attempt at
realism. The character of Tom Wrench is based upon Tom Robinson, who
was the first realist playright. Imogen Parrot is based upon Marie
Wilton, an actress at the fashionable Olympic Theatre, who later
bought and restored the Queen's Theatre in Oxford Street, renaming it
the Prince of Wales (the Pantheon in the play).
Actors played stock characters, for instance General Utility, the
humblest of parts, and Low Comedian. They would not rehearse a
complete text, merely have their own lines written down, known as a
'Part'.
Edmund Kean was the foremost English tragic actor of the nineteenth
century. His son, Charles, was also an actor-manager (hence the
reference to 'Which Kean?').

(http://www.guildplayers.org.uk/productions/trelawnyofthewells.htm)

Arthur Wing Pinero
(born in 1855, knighted in 1909, died in 1934) came from Islington,
left school at 10 and was apprenticed to the law. But amateur acting
was his passion; and at the age of 19 he turned professional. His
first job (salary: £1 a week) was as ‘general utility’ man at the
Theatre Royal, Edinburgh. He took a room in a cheap temperance hotel,
but soon found that it was beyond his means:
‘A young actor, a good simple fellow, with whom I formed firm
friendship, gave me further enlightenment by informing me that only
“stars”— eminent artists who traveled from town to town, who played
leading Shakespearian characters, and were therefore enormously
wealthy—ever thought of putting up at hotels, and that the ordinary
actor invariably dwelt in a modest lodging under the watchful care of
a landlady whose views of the theatrical profession were broad and
generous. To a suitable lodging I was speedily inducted by G---- . . .
For eight months I was a lodger at Balaclava Place; it was there I was
happier than any king in history, richer than any South African
billionaire of today. O busy, cheerful, healthful times! . . .’
    He was to recall and recreate these happy times more than twenty
years later: ‘Trelawny of the “Wells”’ is Pinero’s tribute to
Balaclava Place.
    After ten years as an actor, he made his name as a playwright with
a series of popular farces: ‘The Magistrate’ (1885), ‘The
Schoolmistress’ (1886), ‘Dandy Dick’ (1887). Then, responding to the
Ibsenite revolution that was shaking the European theatre, he took the
town with ‘The Second Mrs. Tanqueray’ (1893)—drawing-room Ibsen, tamed
and diluted to fashionable taste, but a genuine step forward for the
West End theatre of its day. ‘The Nororious Mrs. Ebbsmith’ followed in
1895: another popular ‘play of ideas.’
    ‘Trelawny of the “Wells”’ opened at the Royal Court Theatre on
January 20, 1898, with a cast including Irene Vanbrugh (Trelawny),
Gerald du Maurier (Ferdinand Gadd) and Dion Boucicault, son of the
famous Irish playwright, as Sir William Gower. It ran for 135
performances. Tom Wrench, the idealistic young author, was immediately
recognized as an affectionate portrait of Tom Robertson, the pioneer
of domestic realism, whose ‘cup-and-saucer drama’ had saved the
British theatre of the 1860s from total surrender to farce, melodrama
and melodramatised Shakespeare. (Pinero conceivably saw himself as the
Robertson of the 90s).
    Even Bernard Shaw, who had savaged Pinero’s more serious work, was
won over by the play’s craftsmanship and perfect sense of period. In
‘Our Theatres in the Nineties’ he says that it touched him ‘more than
anything else Mr. Pinero has ever written.’ With Pinero the would-be
modernist Shaw had no patience, but:

‘When he plays me the tunes of 1860, I appreciate and sympathize.
Every stroke touches me: I dwell on the dainty workmanship shown in
the third and fourth acts: I rejoice in being old enough to know the
world of his dreams.’

(http://www.sparrowsp.addr.com/theatre%20pages/trewelawney.htm)

Referring to Marie Effie (nee Wilton, 1839-1921)
(wich Imogen Parrot is based upon)

Sir Squire Bancroft introduced a number of reforms on the British
stage and started the vogue for drawing-room comedy and drama in the
place of melodrama, together with his wife Marie Effie (nee Wilton,
1839-1921). Marie Wilton, the daughter of provincial actors, was on
the stage from early childhood. She first appeared in London in 1856,
where she made a great success as Perdita in Brough's extravaganza on
'The Winter's Tale'. She continued to play in burlesque, notably at
the Strand in HK Byron's plays, until she decided to go into
management on her own account.

On a borrowed capital of £1,000, of which little remained when the
curtain went up, she opened an old and dilapidated theatre, nicknamed
the 'Dust Hole'. Renamed the Prince of Wales's, charmingly decorated,
and excellently run, it opened on 15 Apr 1865. In the company was
Squire Bancroft, who had made his first appearance on the stage in the
provinces in 1861, and had played with Marie Wilton in Liverpool.

The new venture was a success - the despised 'Dust Hole' became one of
the most popular theatres in London, and there the Bancrofts (who had
married in 1867) presented and acted in the plays Of Tom Robertson.
The Bancrofts did much to raise the economic status of actors, paying
higher salaries than elsewhere and providing the actresses' wardrobes.
Among other innovations, they adopted Mme Vestris's idea of
practicable scenery. In 1880 they moved to the Haymarket and continued
their successful career, retiring in 1885. There can be no doubt that
they had a great and salutary influence upon the English stage.
Happily married and of congenial temperaments, they commanded the
highest respect from their staff and audiences, and the knighthood
conferred upon Bancroft in 1897 was a recognition of the services of
both to their profession.

From Phyllis Hartnoll, The Concise Oxford Companion to the
Theatre (c) OUP 1972

This book would be a help, if you could get hold of a copy. It's long
out of print, I'm afraid:

Arundell, Dennis. The Story of Sadler's Wells 1683-1964. London:
Hamish Hamilton, 1965

There are plenty of cheap copies available of the Dennis Arundell book
via www.bookfinder.com