Thank you, CR, an exceedingly well-informed and lucid commentary. Eg Ron Schuchard recently once mentioned Eliot's correspondence with Mary Trevelyan on the prospect of marriage, but don't think it was generally known-about in any detail.
The only inaccuracy I think is that Valerie / the Eliot Estate forbade Ackroyd from quoting *any* part of Eliot's work or correspondence.
Incidentally YouTube has a 2009 BBC TV 'Arena' Documentary, which features many of Valerie's lovingly-preserved scrapbooks recording their life together; her charm bracelets etc etc - it's very touching / fascinating.
a very painstaking, insightful write-up in The Telegraph